The Ancient Green Blobs of the Andes

Photo by Atlas of Wonders licensed under CC BY-NC-ND 2.0

Curious images of these strange green mounds make the rounds of social media every so often. What kind of alien life form is this? Is it a moss? Is it a fungus? The answer may surprise you!

These large, green mounds are comprised of a colony of plants in the carrot family! The Yareta, or Azorella compacta, hails from the Andes and only grows between 3,200 and 4,500 meters (10,500 - 14,750 ft) in elevation. Its tightly compacted growth habit is an adaptation to its high elevation lifestyle. Cushion growth like this helps these plants prevent heat and water loss in these cold, dry, windy environments.

Every so often, these mats erupt with tiny flowers, which must be a sight to behold! Photo by Lon&Queta licensed under CC BY-NC-SA 2.0

As you might imagine, these plants are extremely slow growers. By studying their growth rates over time, experts estimate that individual colonies expand at the rate of roughly 1.5 cm each year. By extrapolating these rates to the measurements of large colonies, we get a remarkable picture of how old some of these plants truly are. Indeed, some of the largest colonies are estimated at over 3000 years old, making them some of the oldest living organisms on the planet!

Sadly, the dense growth of the plant makes it highly sought after as a fuel source. Massive chunks of these plants are harvested with pick axes and burned as a source of heat. Due to their slow growth rate, overharvesting in recent years has caused a serious decline in Yareta populations. Local governments have since enacted laws to protect this species in hopes that it will give colonies the time they need to recover. Indeed, some recovery has already been documented, however, continued monitoring and management will be needed to ensure their populations remain viable into the foreseeable future.

Photo Credits: [1] [2]

Further Reading: [1] [2] [3]

Fraser Fir: A New Look at an Old Friend

Photo by James St. John licensed under CC BY 2.0

Growing up, Fraser fir (Abies fraseri) was a fairly common sight in our house. Each winter this species would usually win out over other options as the preferred tree for our living room during the holiday season. Indeed, its pleasing shape, lovely color, and soft needles have made it one of the most popular Christmas trees around the world. Amazingly, despite its popularity as a decoration, Fraser fir is so rare in the wild that it is considered an endangered species.

Fraser fir is native to only a handful of areas in the southern Appalachian Mountains. Together with red spruce (Picea rubens), this conifer makes up one of the rarest ecosystems on the continent - the southern Appalachian spruce-fir forest. Such forests only exist at elevations above 4,000 ft (1,200 m) from southwestern Virginia to western North Carolina and eastern Tennessee. The reason for this limited distribution is rooted in both modern day climate and North America’s glacial past.

USGS/Public Domain

Whereas anyone hiking through Appalachian spruce-fir forests could readily draw similarities to boreal forests found farther north, the Appalachian spruce-fir forests are nonetheless unique, hosting many species found nowhere else in the world. Indeed, these forests are holdovers from the Pleistocene when the southeast was much cooler than it is today. As glaciers retreated and the climate warmed, Appalachian spruce-fir forests “retreated” up the mountains, following their preferred climate zones until they hit the peaks of mountains and couldn’t go any further.

Indeed, Fraser fir is in large part limited in its distribution by temperature. This conifer does not perform well at high temperatures and is readily out-competed by other species under warmer conditions. Another factor that has maintained Appalachian spruce-fir forests at elevation is fog. The southern Appalachian Mountains host eastern North America’s only temperate rainforest and fog commonly blankets high elevation areas throughout the year. Research has shown that in addition to keeping these areas cool, fog also serves as an important source of water for Fraser fir and its neighbors. As fog condenses on its needles, these trees are able to absorb that water, keeping them hydrated even when rain is absent.

A view of an Appalachian spruce-fir forest from the Blue Ridge Parkway.

Due to its restricted habitat, Fraser fir has never been extremely common. However, things got even worse as Europeans colonized North America. Over the past two centuries, unsustainable logging and grazing practices have decimated southern Appalachian spruce-fir forests, fragmenting them into even smaller patches with no connectivity in between. In areas where thin, rocky soils were not completely washed away, Fraser fir seedlings did return, however, this was not always the case. In areas where soils were were lost, southern Appalachian spruce–fir forests were incapable of regenerating.

If the story ended there, Fraser fir and its habitat would still be in trouble but sadly, things only got worse with the introduction of the invasive balsam woolly adelgid (Adelges piceae) from Europe around 1900. Like the hemlock woolly adlegid, this invasive, sap-feeding insect has decimated Fraser fir populations throughout southern Appalachia. Having shared no evolutionary history with the adelgid, Fraser fir is essentially defenseless and estimates suggest that upwards of 90% of infect trees have been killed by the invasion. Although plenty of Fraser fir seedlings have sprung up in the wake of this destruction, experts fear that as soon as those trees grow large enough to start forming fissures in their bark, the balsam woolly adelgid will once again experience a massive population boom and repeat the process of destruction again.

Dead Fraser fir as seen from Clingman’s Dome. Photo by Brian Stansberry licensed under CC BY 3.0

The loss of Fraser fir from this imperiled ecosystem has had a ripple effect. Fraser fir is much sturdier than its red spruce neighbors and thus provides an important windbreak, protecting other trees from the powerful gusts that sweep over the mountain tops on a regular basis. With a decline in the Fraser fir canopy, red spruce and other trees are more susceptible to blowdowns. Also, the dense, evergreen canopy of these Appalachian spruce-fir forests produces a unique microclimate that fosters the growth of myriad mosses, liverworts, ferns, and herbs that in turn support species like the endangered endemic spruce-fir moss spider (Microhexura montivaga). As Fraser fir is lost from these areas, the species that it once supported decline as well, placing the whole ecosystem at risk of collapse.

The moss-dominated understory of an Appalachian spruce-fir forest supports species found nowhere else in the world. Photo by Miguel.v licensed under CC BY 3.0

Luckily, the plight of this tree and the habitat it supports has not gone unnoticed by conservationists. Numerous groups and agencies are working on conserving and restoring Fraser fir and southern Appalachian spruce-fir forests to at least a portion of their former glory. This is not an easy task by any means. Aside from lack of funding and human power, southern Appalachian spruce-fir forest conservation and restoration is hindered by the ever present threat of a changing climate. Fears that the life-giving fog that supports this ecosystem may be changing make it difficult to prioritize areas suitable for reforestation. Also, the continued threat from invasive species like the balsam woolly adelgid can hamper even the best restoration and conservation efforts. Still, this doesn’t mean we must give up hope. With continued collaboration and effort, we can still ensure that this unique ecosystem has a chance to persist.

Please visit the Central Appalachian Spruce Restoration Initiative (CASRI) website to learn more!

Photo Credits: [1] [2] [4] [5]

Further Reading: [1] [2] [3] [4]

Dwarf Sumac: North America's Rarest Rhus

James Henderson, Golden Delight Honey, Bugwood.org.

In honor of my conversation with Anacardiaceae specialist, Dr. Susan Pell, I wanted to dedicate some time to looking at a member of this family that is in desperate need of more attention. I would like you to meet the dwarf sumac (Rhus michauxii). Found only in a few scattered locations throughout the Coastal Plain and Piedmont regions of southeastern North America, this small tree is growing increasingly rare.

Dwarf sumac is a small species, with most individuals maxing out around 1 - 3 feet (30.5 – 91 cm) in height. It produces compound fuzzy leaves with wonderfully serrated leaflets. It flowers throughout early and mid-summer, with individuals producing an upright inflorescence that is characteristic of what one might expect from the genus Rhus. Dwarf sumac is dioecious, meaning individual plants produce either male or female flowers. Also, like many of its cousins, dwarf sumac is highly clonal, sending out runners in all directions that grow into clones of the original. The end result of this habit is large populations comprised of a single genetic individual producing only one type of flower.

Current range of dwarf sumac (Rhus michauxii). Green indicates native presence in state, Yellow indicates present in county but rare, and Orange indicates historical occurrence that has since been extirpated. [SOURCE]

Research indicates that the pygmy sumac was likely never wide spread or common throughout its range. Its dependence on specific soil conditions (namely sandy or rocky, basic soils) and just the right amount of disturbance mean it is pretty picky as to where it can thrive. However, humans have pushed this species far beyond natural tolerances. A combination of agriculture, development, and fire sequestration have all but eliminated most of its historical occurrences.

Today, the remaining dwarf sumac populations are few and far between. Its habit of clonal spread complicates matters even more because remaining populations are largely comprised of clonal offshoots of single individuals that are either male or female, making sexual reproduction almost non-existent in most cases. Also, aside from outright destruction, a lack of fire has also been disastrous for the species. Dwarf sumac requires fairly open habitat to thrive and without regular fires, it is readily out-competed by surrounding vegetation.

A female infructescence. Photo by Alan Cressler

Luckily, dwarf sumac has gotten enough attention to earn it protected status as a federally listed endangered species. However, this doesn’t mean all is well in dwarf sumac land. Lack of funding and overall interest in this species means monitoring of existing populations is infrequent and often done on a volunteer basis. At least one study pointed out that some of the few remaining populations have only been monitored once, which means it is anyone’s guess as to their current status or whether they still exist at all. Some studies also indicate that dwarf sumac is capable of hybridizing with related species such as whinged sumac (Rhus copallinum).

Another complicating factor is that some populations occur in some surprisingly rundown places that can make conservation difficult. Because dwarf sumac relies on disturbance to keep competing vegetation at bay, some populations now exist along highway rights-of way, roadsides, and along the edges of artificially maintained clearings. While this is good news for current population numbers, ensuring that these populations are looked after and maintained is a difficult task when interests outside of conservation are involved.

Some of the best work being done to protect this species involves propagation and restoration. Though still limited in its scope and success, out-planting into new location in addition to augmenting existing populations offers hope of at least slowing dwarf sumac decline in the wild. Special attention has been given to planting genetically distinct male and female plants into existing clonal populations in hopes of increasing pollination and seed set. Though it is too early to count these few attempts as true successes, they do offer a glimmer of hope. Other conservation attempts involve protecting what little habitat remains for this species and encouraging better land management via prescribed burns and invasive species removal.

The future for dwarf sumac remains uncertain, but that doesn’t mean all hope is lost. With more attention and research, this species just may be saved from total destruction. The plight of species like the dwarf sumac serve as an important reminder of why both habitat conservation and restoration are so important for slowing biodiversity loss.

Photo Credits: [1] [2] [3]

Further Reading: [1] [2] [3]James Henderson, Golden Delight Honey, Bugwood.org.

A Tree That Makes Poisonous Rats

For many organisms, poisons are an effective means to keep from being eaten. However, making poisons can be costly. Depending on the compounds involved, poison synthesis can require a lot of nutrients that could be directed elsewhere. This is why some animals acquire poisons through their diet. Take, for instance, the monarch butterfly. As its caterpillars feed on milkweed, they sequester the milkweed toxins in their tissues, which makes them unpalatable into adulthood. Cases like this abound in the invertebrate world, but recently scientists have confirmed that at least one mammal has evolved a similar strategy.

Meet the African crested rat (Lophiomys imhausi). Its large size and bold color patterns make it look like the result of a passionate encounter between a porcupine and a skunk. However, it is 100% rat and it has a fascinating defense strategy that begins with a tree native throughout parts of eastern Africa aptly referred to as the poison arrow tree (Acokanthera schimperi).

An African crested rat displaying its crest of toxic hairs and aposematic color pattern. [SOURCE]

The poison arrow tree is a member of the milkweed family (Apocynaceae), and like many of its relatives, this species produces potent toxins that can cause heart failure. The toxic nature of this tree has not been lost on humans. In fact, the particular strain of toxin it produces is referred to as ouabaïne or “arrow poison” as indigenous peoples have been coating their arrows with its sap for millennia. It turns out that humans aren’t the only mammals to find use for this sap either. The African crested rat uses it too.

The African crested rat grows highly specialized crest of hairs along its back. These hairs are thick and porous and when the rat feels threatened, it erects the crest and shows off its stark black and white coloring. It has been noted in the past that predators such as dogs that try to eat the rat run the risk of collapsing into convulsions and dying so the idea was put forth that that crest of hairs was toxic. Only recently has this been confirmed.

By studying a group of these rodents, scientists observed an interesting behavior. Many of the rats in their study would chew and lick twigs and branches of the poison arrow tree and then chew and lick their crest. What this behavior does is transfer the plant toxins onto those specialized hairs. The high surface area of each hair means they can soak up a lot of the toxins. Surprisingly, the rats appear to be resistant to the sap’s toxic effects. Perhaps they possess modified sodium pumps in their heart muscles that counter the effects of the toxin. Or, they may possess a highly specialized gut flora that breaks down the toxins. Either way, the rats do not show any signs of poisoning from this behavior.

A close-up view of the African crested rat’s poison anointed hairs. Photo by Sara B. Weinstein

The rats don’t have to do this very often to remain poisonous. By talking with locals that still use the poison arrow tree sap on their arrows, researchers learned that the compounds are extremely stable. Once coated, arrows will remain toxic for years. As such, the African crested rat likely doesn’t need constant application for this defense mechanism to remain effective.

As far as we know, this is the first example of a mammal sequestering plant toxins as a form of defense. It is amazing to think that a defense strategy evolved by a plant to avoid being eaten can be co-opted by a rat so that it too can avoid being eaten. Sadly, it is feared that this unique relationship between rat and tree is starting to disappear. Though more research is needed to accurately assess their numbers, there is growing evidence that African crested rats are on the decline. Hopefully with a bit more attention, these trends can be properly assessed and conservation measures can be put into place. In the meantime, please avoid putting any and all rats in your mouth.

Photo Credits: [1] [2] [3] [4]

Further Reading: [1]

A Rare Case of Ant Pollination in Australia

Photo by Nicola Delnevo [SOURCE]

Ants have struck up a lot of interesting and important relationships with plants. They disperse seeds, protect plants from herbivores and disease, and can even help acquire nutrients. For all of the beneficial ways in which ants and plants interact, pollination rarely enters into the equation. More often than not, ants are actually detrimental to the sex lives of flowering plants. Such is not the case for a rare species of protea endemic to Western Australia called the smokebush (Conospermum undulatum).

The reason ants usually suck at pollination is thanks to a tiny organ called the metapleural gland. For many ant species, this gland secretes special antimicrobial fluids that the ants use to groom themselves. Because ants tend to live in high densities in close quarters, this antimicrobial fluid helps keep their little bodies clean of any pathogens that might threaten their existence. For as good as these fluids are for ants, they destroy pollen grains, rendering them useless for pollination.

Leioproctus conospermi. Photo by Sarah McCaffrey licensed under CC BY-ND 2.0.

As is so often the case in nature, there are always exceptions to the rule and it seems that one such exception is playing out in Western Australia. While investigating the reproductive ecology of the smokebush, researchers noted that ants were regular visitors to their small flowers. They knew that in drier climates, some ant species have evolved to produce considerably less antimicrobial fluids. The thought is that drier climates tend to harbor fewer microbial pathogens and thus ants don’t need to waste as much energy protecting themselves from such threats. If this was the case in Western Australia then it was entirely possible that ants could potentially serve as pollinators for this plant. Armed with this hypothesis, they decided to take a closer look.

It turns out that the floral morphology of the smokebush lends well to visiting ant anatomy. The tiny flowers produce a small amount of nectar at the base. As ants shove their heads down into the flower to get a drink, it triggers an explosive mechanism that causes the style the smack down onto the back of the ant. In doing so, it also mops up any pollen the ant may be carrying. At the same time, the anthers explosively dehisce, coating the visitor with a fresh dusting of pollen. During their observations, researchers noted that ants weren’t the only insects visiting smokebush blooms. They also noted lots of visitation from invasive honeybees (Apis mellifera) and a tiny native bee called Leioproctus conospermi.

(A) White flowers of Conospermum undulatum. (B) Floral details. (C–H) Insects visiting flowers of C. undulatum: (C) Leioproctus conospermi; (D) Camponotus molossus; (E) Camponotus terebrans; (F) Iridomyrmex purpureus; (G) Myrmecia infima; (H) Apis mellifera. [SOURCE]

After recording visits, researchers needed to know whether any of these floral visitors resulted in successful pollination. After all, just because something visits a flower doesn’t mean it has what it takes to get the job done for the plant. By looking at differences in seed set between ant and bee visitors, they were able to paint a fascinating picture of the pollination ecology of the rare smokebush.

It turns out that ants are indeed excellent pollinators of this shrub, contributing just as much to overall seed set as the tiny native Leioproctus conospermi. Alternatively, invasive honeybees barely functioned as pollinators at all. Their heads were too big to effectively trigger the pollination mechanism of the flowers but nonetheless were able to access the nectar within. As such, honeybees are considered nectar thieves for the smokebush, harming its overall reproductive effort rather than helping.

Amazingly, the effectiveness of ants as smokebush pollinators is not because they produce less antimicrobial fluids. In fact, these ants were fully capable of producing ample amounts of these pollen-killing substances. Instead, it appears that the plant itself has evolved to tolerate ant visitors. Smokebush pollen is resistant to the toxic effects of the metaplural gland fluids. With plenty of hungry ants always on the lookout for food, the smokebush has managed to tap in to an abundant and reliable vector for pollination. No doubt other examples exist, we simply have to go looking.

Photo Credits: [1] [2] [3]

Further Reading: [1]

Mysterious Franklinia

Photo by Tom Potterfield licensed by CC BY-NC-SA 2.0

In 1765, a pair of botanists, John and William Bartram, observed "several very curious shrubs" growing in one small area along the banks of the Altamaha River in what is now Georgia. Again in 1773, William Bartram returned to this same area. He reported that he "was greatly delighted at the appearance of two beautiful shrubs in all their blooming graces. One of them appeared to be a species of Gordonia, but the flowers are larger, and more fragrant than those of the Gordonia lasianthus.” The species Bartram was referring to was not a Gordonia, but rather a unique species in a genus all of its own. After years of study, Bartram would name the plant in honor of a close family friend, Benjamin Franklin.

This tree is none other than the Franklin tree - Franklinia alatamaha. This beautiful member of the tea family (Theaceae) is unique in that it no longer exists outside of cultivation. It is completely extinct in the wild. However, this is not a recent extinction brought on by the industrialization of North America. IT would seem that Franklinia was nearing extinction before Europeans ever made it to North America. As Bartram first noted "We never saw it grow in any other place, nor have I ever since seen it growing wild, in all my travels, from Pennsylvania to Point Coupe, on the banks of the Mississippi, which must be allowed a very singular and unaccountable circumstance; at this place there are two or 3 acres of ground where it grows plentifully." Indeed, no reports of this species came from anywhere other than that two to three acre section of land on he banks of the Altamaha River. The last confirmed sighting of Franklinia in the wild was in 1790.

Photo by Krzysztof Ziarnek, Kenraiz licensed by CC BY-SA 4.0

What happened to Franklinia? The truth is, no one really knows. Many theories have been put forth to try to explain the disappearance of this unique shrub. What can be agreed on at this point is that Franklinia was probably mostly extinct by the time Europeans arrived. One thought is that it was a northern species that "escaped" glaciation thanks to a few scattered populations in southeastern North America. Indeed, it has been well documented that plants grown in the northern US fare a lot better than those grown in the south. It is thought that perhaps Franklinia was not well adapted to the hot southern climate and slowly dwindled in numbers before it had a chance to expand its range back north after the glaciers retreated.

Others blame early botanists for collecting this already rare species out of existence. What few trees may have remained could easily have been whipped out by a stochastic event like a flood or fire. Another possibility is that habitat loss from Indigenous and subsequent European settlement coupled with disease introduced via cotton farming proved too much for a small, genetically shallow population to handle. In my opinion, it was probably the combination of all of these factors that lead to the extinction of Franklinia in the wild.

Photo by Tony Rodd licensed by CC BY-NC-SA 2.0

Anyone growing this tree may notice some funny aspects of its ecology. For instance, it blooms in September, which is a lot later than most North American flowering tree species. Also, the fruits take a long time to mature, needing 13 - 15 months on the tree to be viable. The combination of these strange quirks of Franklinia biology as well as its inability to handle drought (a condition quite common in its only known natural range in Georgia), lends credence to the glacial retreat theory.

We do owe Bartram though. Without him, this species may have disappeared entirely. During his expeditions to Georgia, he collected a few seeds from that Franklinia population. Any Franklinia trees growing in gardens today are direct descendants of those original collections. Franklinia is yet another plant species kept alive by cultivation. Without its addition to gardens all over the country, this species would have been lost forever, living on in our minds as illustrations and herbarium specimens.

Photo Credits: [1] [2] [3]

Further Reading: [1] [2] [3] [4]

Sea Oats: Builder of Dunes & Guardian of the Coast

Photo by Sara Johnson

Coastal habitats can be really unforgiving to life. Anything that makes a living along the coast has to be tough and they don’t come much tougher than sea oats (Uniola paniculata). This stately grass can be found growing along much of the Atlantic coast of North America as well as along the Gulf of Mexico. What’s more, its range is expanding. Not only is this grass extremely good at living on the coast, it is a major reason coastal habitats like sand dunes exist in the first place. Its presence also serves to protect coastlines from the damaging effects of storm surges. What follows is a celebration of this amazing ecosystem engineer.

Sea oats is a dominant player in coastal plant communities. Few other species can hold a candle to its ability to survive and thrive in conditions that are lethal to most other plants. The ever-present winds that blow off the ocean bring with them plenty of sand and salt spray. Sea oats takes this in strides. Not only are its tissues extremely tough, they also help prevent too much water loss in a system defined by desiccation.

Photo © Don Henise licensed by CC BY 2.0

The life cycle of sea oats begins with seeds. Its all about numbers for this species and seat oats certainly produces a lot of seed. Surprisingly, many of the seeds produced are not viable. What’s more, most will never make it past the seedling stage. You see, sea oat seeds require just the right amount of burial in sand to germinate and establish successfully. Too shallow and they are either picked off by seed predators or the resulting seedlings quickly dry up. Too deep and the limited reserves within mean the seedling exhausts itself before it can ever reach the surface.

Still, enough seeds germinate from year to year that new colonies of sea oats are frequently established. Given the right amount of burial, seedlings focus much of their first few months on developing a complex, albeit shallow root system. Within two months of germination, a single sea oat can grow a root system that is as much as 10 times the size of the rest of the plant. This is because sand is not a forgiving growing medium. Sand is constantly shifting, it does not hold on to water very long, and it is usually extremely low in nutrients. By growing a large, shallow root system, sea oats are able to not only anchor themselves in place, they are also able to take advantage of what limited water and nutrients are available.

It is also this intense root growth that makes sea oats such an important ecosystem engineer in coastal habitats. All of those roots hold on to sand extremely well. Add to that some vast mychorrhizal fungi partnerships and you have yourself a recipe for serious erosion control. The interesting thing is that as sea oats grow larger, they trap more sand. As more sand builds up around the plants, they grow even larger to avoid burial. This process snowballs until an entire dune complex develops. As the dunes stabilize, more plants are able to establish, which in turn attracts more organisms into the community. A literal ecosystem is built from sand thanks to the establishment of a single species of grass.

Photo © Hans Hillewaert / CC BY-SA 4.0

As sea oats mature, they will begin to produce flowers, and the process repeats itself over and over again. As mentioned above, the sea oats seeds are subject to a lot of seed predation. This means that as sea oat populations grow, more and more animals can find food in and among the dunes. So, not only do sea oats build the habitat, they also supply it with plenty of resources for organisms to utilize.

The power of sea oats does not end there. Because they are so good at controlling erosion, they help stabilize the shoreline from the punishing blow of storm surges. Dune systems, especially those of barrier islands, help reduce the amount of erosion and the momentum of wave action reaching coastal communities. Many states here in North America are starting to realize this and are now protecting sea oat populations as a result.

Sea oats, though tough, are not indestructible. We humans can do a lot of damage to these plants and the communities they create simply by walking or driving on them. Pathways from foot and vehicle traffic kill off the dune vegetation and create a path of least resistance for wind, which quickly erodes the dunes. Apart from that, development and resulting runoff also destroy sensitive dune communities, making our coastlines that much more vulnerable to the inevitable storms that threaten their very existence.

As our climate continues to change at an unprecedented rate and storms grow ever stronger, it is very important that we recognize the role important species like sea oats play in not only providing habitat, but also protecting our coastlines. Dune stabilization and restoration projects are growing in popularity as a cost effective solution to some of the threats facing coastal communities. Among the many techniques for restoring dunes is the planting of native dune building species like sea oats. If you live near or simply like to enjoy the coast, please stay off the dunes. Foot and vehicle traffic make quick work of these habitats and we simply cannot afford less of them.

Watch our short film DUNES to learn more about these incredible ecosystems.

Photo Credits: [1] [2] [3]

Further Reading: [1] [2] [3] [4] [5]

Let's Talk About Recruitment

Photo by --Tico-- licensed by CC BY-NC-ND 2.0

For any species to be considered successful, it must replace itself generation after generation. We call this process recruitment and it is very important. After all, reproduction is arguably the most fundamental aspect of life in a Darwinian sense. For plants, this can be done either vegetatively or sexually via seeds and spores. Though vegetative reproduction is a fundamental process for many plants around the globe, seed or spore germination is arguably the most important. To truly understand what a plant needs, we have to understand its germination requirements.

Recruitment is a considerable limiting factor for plant populations. In fact, it is the first major bottleneck plants must pass through. It is estimated that a majority of plant mortality occurs during the germination and seedling stages. However, not all plants are equal in this way. Some plants are considered seed or propagule limited whereas others are habitat limited.

If a plant is seed limited, it means that its ability to expand its population or colonize new habitats its limited by the ability of seeds (or spores) to make it to a new location. Once there, nature takes its course and germination occurs with little impediment. If a plant is habitat limited, however, things get a bit more tricky. For habitat limited plants, simply getting seeds to a new location is not enough. Some other aspect of the environment (soil moisture, texture, temperature, disturbance, etc.) limit successful germination. Only when the right conditions are present can habitat limited plants germinate and begin to grow.

Habitat limitation is probably the most common limit to plant establishment. Simply put, not all plants will be successful everywhere. Even the successful growth and persistence of adult plants can be poor predictors of seedling success. Many plants can live for decades or even centuries and the conditions that were present when they germinated may have long since changed. Even the presence of the adults themselves can make a site unsuitable for germination. Think of all of those fire adapted species out there that require the entire community to burn before their seeds will ever germinate.

In reality, it is likely that most plants are habitat limited to some degree. These are not binary categories after all, rather they are aligned along a spectrum of possibilities. The fact that most plants don’t completely take over an area once seeds or spores arrive is proof of the myriad limits to plant establishment. As such, recruitment limitation is extremely important to study. It can make a huge difference in the context of conservation and restoration. Even the successful establishment of adult plants is no guarantee that seedlings stand a chance. Without successful recruitment, all you have left is a nice garden that is doomed to run its course. By understanding the limits to plant recruitment, we can do much more than just improve on our ability to protect and bolster plant populations, we can also gain insights into why so many plants remain rare on the landscape and so few ever rise to dominance.

Photo Credits: [1]

Further Reading: [1] [2]

Botanical Buoys

Photo by Doug McGrady licensed under CC BY 2.0

American featherfoil (Hottonia inflata) is a fascinating aquatic plant. It can be found in wetlands ranging from the coastal plains of Texas all the way up into Maine. Though widespread, American featherfoil is by no means common. Today I would like to introduce you to this gorgeous member of the primrose family (Primulaceae).

American featherfoil may look like a floating plant but it is not. It roots itself firmly into the soil and spends much of its early days as a vegetative stem covered in wonderful feathery leaves. It may be hard to find during this period as no part of it sticks above the water. To find it, one must look in shallow waters of ponds, ditches, and swamps that have not experienced too much disturbance. More on this in a bit.

Photo by Doug McGrady licensed under CC BY 2.0

American featherfoil lives life in the fast lane. It is what we call a winter annual. Seeds germinate in the fall and by late October, juveniles can be seen sporting a few leaves. There it will remains throughout the winter months until early spring when warming waters signal the growth phase. Such growth is rapid. So rapid, in fact, that by mid to late April, plants are beginning to flower. To successfully reproduce, however, American featherfoil must get its flowers above water.

The need to flower out of water is exactly why this plant looks like it is free floating. The flower stalks certainly do float and they do so via specialized stems, hence the specific epithet “inflata.” Each plant grows a series of large, spongy flowering stalks that are filled with air. This helps buoy the stems up above the water line. It does not float about very much as its stem and roots still anchor it firmly into place. Each inflorescence consists of a series of whorled umbels that vary in color from white to yellow, and even violet. Following pollination, seeds are released into the water where they settle into the mud and await the coming fall.

Photo by Doug McGrady licensed under CC BY 2.0

As I mentioned above, American featherfoil appreciates wetland habitats that haven’t experienced too much disturbance. Thanks to our wanton disregard for wetlands over the last century or so, American featherfoil (along with countless other species) has seen a decline in numbers. One of the biggest hits to this species came from the trapping of beavers. It turns out, beaver ponds offer some of the most ideal conditions for American featherfoil growth. Beaver ponds are relatively shallow and the water level does not change drastically from month to month.

Historically unsustainable levels of beaver trapping coupled with dam destruction, wetland draining, and agricultural runoff has removed so much suitable habitat and with it American featherfoil as well as numerous wetland constituents. Without habitat, species cannot persist. Because of this, American featherfoil has been placed on state threatened and endangered lists throughout the entirety of its range. With the return of the beaver to much of its former range, there is hope that at least some of the habitat will again be ready for American featherfoil. Still, our relationship with wetlands remains tenuous at best and until we do more to protect and restore such important ecosystems, species like American featherfoil will continue to suffer. This is why you must support wetland protection and restoration in your region!

Photo Credits: [1] [2] [3]

Further Reading: [1] [2]

Maxipiñon: One of the Rarest Pines in the World

Photo by Ruff tuff cream puff licensed under public domain

The maxipiñon (Pinus maximartinezii) is one of the rarest pines on Earth. A native of southern Sierra Madre Occidental, Mexico, nearly all individuals of this species can be found scattered over an area that collectively spans only about 3 to 6 square miles (5 – 10 km²) in size. Needless to say, the maxipiñon teeters on the brink of extinction. As a result, a lot of effort has been put forward to better understand this species and to develop plans aimed at ensuring it is not lost forever.

The maxipiñon has only been known to science for a few decades. It was described back in 1964 after botanist Jerzy Rzedowski noted some exceptionally large pine seeds for sale at a local market. He named the species in honor of Maximino Martínez, who contributed greatly to our understanding of Mexican conifers. However, it was very obvious that the maxipiñon was well known among the residents of Zacatecas.

The reason for this are its seeds. The maxipiñon is said to produce the largest and most nutritious seeds of all the pines. As such, it is a staple of the regional diet. Conversations with local farmers suggest that it was much more common as recent as 60 years ago. Since then, its numbers have been greatly reduced. It soon became apparent that in order to save this species, we had to learn a lot more about what threatens its survival.

The most obvious place to start was recruitment. If any species is to survive, reproduction must outpace death. A survey of local markets revealed that a lot of maxipiñon seeds were being harvest from the wild. This would be fine if maxipiñon were widespread but this is not the case. Over-harvesting of seeds could spell disaster for a species with such small population sizes.

Indeed, surveys of wild maxipiñon revealed there to be only 2,000 to 2,500 mature individuals and almost no seedlings. However, mature trees do produce a considerable amount of cones. Therefore, the conclusion was made that seed harvesting may be the single largest threat to this tree. Subsequent research has suggested that seed harvests actually may not be the cause of its rarity. It turns out, maxipiñon population growth appears to be rather insensitive to the number of seeds produced each year. Instead, juvenile tree survival seems to form the biggest bottleneck to population growth.

Photo by Krzysztof Ziarnek, Kenraiz licensed under CC BY-SA 4.0

You see, this tree appears to be more limited by suitable germination sites than it does seed numbers. It doesn’t matter if thousands of seeds are produced if very few of them ever find a good spot to grow. Because of this, scientists feel that there are other more serious threats to the maxipiñon than seed harvesting. However, humans are still not off the hook. Other human activities proved to be far more damaging.

About 50 years ago, big changes were made to local farming practices. More and more land was being cleared for cattle grazing. Much of that clearing was done by purposefully setting fires. The bark of the maxipiñon is very thin, which makes it highly susceptible to fire. As fires burn through its habitat, many trees are killed. Those that survive must then contend with relentless overgrazing by cattle. If that wasn’t enough, the cleared land also becomes highly eroded, thus further reducing its suitability for maxipiñon regeneration. Taken together, these are the biggest threats to the ongoing survival of this pine. Its highly fragmented habitat no longer offers suitable sites for seedling growth and survival.

As with any species this rare, issues of genetic diversity also come into play. Though molecular analyses have shown that maxipiñon does not currently suffer from inbreeding, it has revealed some interesting data that give us hints into the deeper history of this species. Written in maxipiñon DNA is evidence of an extreme population bottleneck that occurred somewhere between 400 and 1000 years ago. It appears that this is not the first time this tree has undergone population decline.

There are a few ways in which these data can be interpreted. One is that the maxipiñon evolved relatively recently from a small number of unique and isolated individuals. Perhaps a hybridization event occurred between two closely related piñon species - the weeping piñon (Pinus pinceana) and Nelson piñon (Pinus nelsonii). Another possibility, which does not rule out hybridization, is that the maxipiñon may actually be the result of artificial selection by agriculturists of the region. Considering the value of its seeds today, it is not hard to imagine farmers selecting and breeding piñon for larger seeds. It goes without saying that these claims are largely unsubstantiated and would require much more evidence to say with any certainty, however, there is plenty of evidence that civilizations like the Mayans were conserving and propagation useful tree species much earlier than this.

Despite all we have learned about the maxipiñon over the last few decades, the fate of this tree is far from secure. Ex situ conservation efforts are well underway and you can now see maxipiñon specimens growing in arboreta and botanical gardens around the world. Seeds from these populations are being used for storage and to propagate more trees. Sadly, until something is done to protect the habitat on which it relies, there is no telling how long this species will last in the wild. This is why habitat conservation efforts are so important. Please support local land conservation efforts in your area because the maxipiñon is but one species facing the loss of its habitat.

Photo Credits: [1] [2] [3] [4]

Further Reading [1] [2] [3]

The Golden Fuchsia: A Case Study in Why Living Collections Matter

Photo by FarOutFlora licensed under CC BY-NC-ND 2.0

The golden Fuchsia (Deppea splendens) is a real show stopper. It is impossible to miss this plant when it is in full bloom. Amazingly, if it were not for the actions of one person, this small tree may have disappeared without anyone ever knowing it existed in the first place. The golden Fuchsia is yet another plant that currently exists only in cultivation.

The story of the golden Fuchsia starts in the early 1970’s. During a trek through the mountains of southern Mexico, Dr. Dennis Breedlove, then the curator of botany for the California Academy of Sciences, stumbled across a peculiar looking shrub growing in a steep canyon. It stood out against the backdrop of Mexican oaks, pines, and magnolias. Standing at about 15 to 20 feet tall and adorned with brightly colored, pendulous inflorescences, it was clear that this species was something special indeed.

Photo by FarOutFlora licensed under CC BY-NC-ND 2.0

A subsequent expedition to Chiapas in the early 1980’s was aimed at collecting seeds of this wonderful plant. It turned out to be relatively easy to germinate and grow, provided it didn’t experience any hard frost events. Plants were distributed among botanical gardens and nurseries and it appeared that the golden Fuchsia was quickly becoming something of a horticultural treasure. Despite all of the attention it was paid, the golden Fuchsia was only properly described in 1987.

Sadly, around the same time that botanists got around to formally naming the plant, tragedy struck. During yet another trip to Chiapas, Dr. Breedlove discovered that the cloud forest that once supported the only known population of golden Fuchsia had been clear cut for farming. Nothing remained but pasture grasses. No other wild populations of the golden Fuchsia have ever been found.

Photo by Stickpen licensed under public domain

If it was not for those original seed collections, this plant would have gone completely extinct. It owes its very existence to the botanical gardens and horticulturists that have propagated it over the last 30+ years. All of the plants you will encounter today are descendants of that original collection.

The role of ex situ living collections play in the conservation of species is invaluable. The golden Fuchsia is yet another stark reminder of this. If it were not for people like Dr. Breedlove and all of the others who have dedicated time and space to growing the golden Fuchsia, this species would have only been known as a curious herbarium specimen. The most alarming part about all of this is that as some botanical gardens continue to devalue living collections in favor of cheap landscaping and event hosting, living collections are getting pushed to the side, neglected, or even worse, destroyed. We must remember that living collections are a major piece of the conservation puzzle and their importance only grows as we lose more and more wild spaces to human expansion.

Photo Credits: [1] [2] [3]

Further Reading: [1] [2]

Resurrecting Café Marron

Photo by Tim Waters licensed under CC BY-NC-ND 2.0

Back in 1980, a school teacher on the island of Rodrigues sent his students out to look for plants. One of the students brought back a cutting of a shrub that astounded the botanical community. Ramosmania rodriguesii, more commonly known as café marron, was up until that point only known from one botanical description dating back to the 1800's. The shrub, which is a member of the coffee family, was thought to have been extinct due to pressures brought about during the colonization of the island (goats, invasive species, etc.). What the boy brought back was indeed a specimen of café marron but the individual he found turned out to be the only remaining plant on the island.

News of the plant quickly spread. It started to attract a lot of attention, not all of which was good. There is a belief among the locals that the plant is an herbal remedy for hangovers and venereal disease (hence its common name translates to ‘brown coffee’) and because of that, poaching was rampant. Branches and leaves were being hauled off at a rate that was sure to kill this single individual. It was so bad that multiple layers of fencing had to be erected to keep people away. It was clear that more was needed to save this shrub from certain extinction.

Cuttings were taken and sent to Kew. After some trial and tribulation, a few of the cuttings successfully rooted. The clones grew and flourished. They even flowered on a regular basis. For a moment it looked like this plant had a chance. Unfortunately, café marron did not seem to want to self-pollinate. It was looking like this species was going to remain a so-called “living dead” representative of a species no longer able to live in the wild. That is until Carlos Magdalena (the man who saved the rarest water lily from extinction) got his hands on the plants.

The key to saving café marron was to somehow bypass its anti-selfing mechanism. Because so little was known about its biology, there was a lot of mystery surrounding its breeding mechanism. Though plenty of flowers were produced, it would appear that the only thing working on the plant were its anthers. They could get viable pollen but none of the stigmas appeared to be receptive. Could it be that the last remaining individual (and all of its subsequent clones) were males?

This is where a little creativity and a lot of experience paid off. During some experiments with the flowers, it was discovered that by amputating the top of the stigma and placing pollen directly onto the wound one could coax fertilization ans fruiting. From that initial fruit, seven seeds were produced. These seeds were quickly sent to the propagation lab but unfortunately the seedlings were never able to establish. Still, this was the first indication that there was some hope left for the café marron.

After subsequent attempts at the stigma amputation method ended in failure, it was decided that perhaps something about the growing conditions of the first plant were the missing piece of this puzzle. Indeed, by repeating the same conditions the first individual was exposed to, Carlos and his team were able to coax some changes out of the flowering efforts of some clones. Plants growing in warmer conditions started to produce flowers of a slightly different morphology towards the end of the blooming cycle. After nearly 300 attempts at pollinating these flowers, a handful of fruits were formed!

From these fruits, over 100 viable seeds were produced. What’s more, these seeds germinated and the seedlings successfully established. Even more exciting, the seedlings were a healthy mix of both male and female plants. Carlos and his team learned a lot about the biology of this species in the process. Thanks to their dedicated work, we now know that café marron is protandrous meaning its male flowers are produced before female flowers.

However, the story doesn’t end here. Something surprising happened as the seedlings continued to grow. The resulting offspring looked nothing like the adult plant. Whereas the adult plant has round, green leaves, the juveniles were brownish and lance shaped. This was quite a puzzle but not entirely surprising because the immature stage of this shrub was not known to science. Amazingly, as the plants matured they eventually morphed into the adult form. It would appear that there is more to the mystery of this species than botanists ever realized. The question remained, why go through such drastically different life stages?

The answer has to do with café marron's natural predator, a species of giant tortoise. The tortoises are attracted to the bright green leaves of the adult plant. By growing dull, brown, skinny leaves while it is still at convenient grazing height, the plant makes itself almost invisible to the tortoise. It is not until the plant is out of the range of this armoured herbivore that it morphs into its adult form. Essentially the young plants camouflage themselves from the most prominent herbivore on the island.

Thanks to the efforts of Carlos and his team at Kew, over 1000 seeds have been produced and half of those seeds were sent back to Rodrigues to be used in restoration efforts. As of 2010, 300 of those seed have been germinated, opening up many more opportunities for reintroduction into the wild. Those early trials will set the stage for more restoration efforts in the future. It is rare that we see such an amazing success story when it comes to such an endangered species. We must celebrate these efforts because they remind us to keep trying even if all hope seems to be lost. My hat is off to Carlos and the dedicated team of plant conservationists and growers at Kew.

Photo Credits: [1] [3] [4]

Further Reading: [1] [2]

A New Species of Waterfall Specialist Has Been Discovered In Africa

A. habit, whole plant, in fruit, showing the flat root, a pillar-like ‘haptera’, and a shoot with three inflorescences, B. detail of shoot with three branches, C. view of upper surface of a flattened root, with six short, erect shoots, each with 1–2 1-flowered inflorescences emerging from spathellum remains, D. side view of plant showing, on the lower surface of the flattened root, the pillar-like haptera, branched at base; upper surface of root with spathellum-sheathed inflorescence base, E. plant attached to rock by weft of thread-like root hairs (indicated with arrow) from base of pillar-like haptera; upper surface of flattened root with two shoots, F. side view of flower showing one of two tepals in full frontal view, G. as F. with tepal removed, exposing the gynoecium with, to left, the arched-over androecium, H. side view of flower with androecium in centre, two tepals flanking the gynoecium, I. androecium (leftmost of three anthers missing), J. transverse section of andropodium, K. view of gynoecium from above showing funneliform style-stigma base, L. fruit, dehisced, M. transverse section of bilocular fruit, showing septum and placentae, N. placentae with seeds, divided by septum, O. seeds, P. seed with mucilage outer layer. Drawn by Andrew Brown from Lebbie A2721 [SOURCE]

At first glance, this odd plant doesn’t look very special. However, it is the first new member of the family Podostemaceae to be found in Africa in over 30 years. It has been given the name Lebbiea grandiflora and it was discovered during a survey to assess the impacts of a proposed hydroelectric dam. By examining the specimen, Kew botanists quickly realized this plant was unique. Sadly, if all goes according to plan, this species may not be long for this world unless something is done to preserve it.

Members of the family Podostemaceae are strange plants. Despite how delicate they look, these plants specialize in growing submersed on rocks in waterfalls, rapids, and other fast flowing bodies of water. They are generally small plants, though some species can grow to lengths of 3 ft. (1 m) or more. The best generalization one can make about this group is that they like clean, fast-flowing water with plenty of available rock surfaces to grow on.

Lebbiea grandiflora certainly fits this description. It is native to a small portion of Sierra Leone and Guinea where it grows on slick rock surfaces only during the wet season. As the dry season approaches and the rivers shrink in size, L. grandiflora quickly sets seed and dies.

As mentioned, the area in which this plant was discovered is slated for the construction of a large hydroelectric dam. The building of this dam will most certainly destroy the entire population of this plant. As soon as water slows, becomes more turbid, and sediments build up, most Podostemaceae simply disappear. Unfortunately, I appears this plant was in trouble even before the dam came into the picture.

As mentioned, Podostemaceae need clean rock surfaces on which to germinate and grow. Without them, the seedlings simply can’t get established. Mining operations further upstream of the Sewa Rapids have been dumping mass quantities of sediment into the river for years. All of this sediment eventually makes it down into L. grandiflora territory and chokes out available germination sites.

Alarmed at the likely extinction of this new species, the Kew team wanted to try and find other populations of L. grandiflora. Amazingly, one other population was found growing in a river near Koukoutamba, Guinea. Sadly, the discovery of this additional population is bitter sweet as the World Bank is apparently backing another hydro-electric dam project on that river as well.

The only hope for the continuation of this species currently will be to (hopefully) find more populations and collect seed to establish ex situ populations both in other rivers as well as in captivity if possible. To date, no successful purposeful seeding of any Podostemaceae has been reported (if you know of any, please speak up!). Currently L. grandiflora has been given “Critically Endangered” status by the IUCN and the botanists responsible for its discovery hope that, coupled with the publication of this new species description, more can be done to protect this small rheophytic herb.

Photo Credit: [1] [2]

Further Reading: [1]

The Wild World of Rattan Palms

Photo by Eric in SF licensed under CC BY-SA 4.0

There are a lot of big organisms out there. A small handful of these are truly massive. When someone mentions big plants, minds will quickly drift to giant sequoias or coastal redwoods. These species are indeed massive. The tallest tree on record is a coastal redwood measuring 369 feet tall. That's a whole lot of tree! What some may not realize is that there are other plants out there that can grow much "taller" than even the tallest redwood. For instance, there is a group of palms that hail from Africa, Asia, and Australasia that grow to staggering lengths albeit without the mass of a redwood.

You are probably quite familiar with some of these palm species, though not as living specimens. If you have ever owned or sat upon a piece of wicker furniture then you were sitting on pieces of a rattan palm. Rattan palms do not grow in typical palm tree fashion. Rattans are climbers, more like vines. All palms grow from a central part of the plant called the heart. They grow as bromeliads do, from meristem tissue in the center of a rosette of leaves. As a rattan grows, its stem lengthens and grabs hold of the surrounding vegetation using some seriously sharp, hooked spikes. For much of their early life they generally sprawl across the forest floor but the real goal of the rattan is to reach up into the canopy where they can access the best sunlight.

Photo by Erwin Bolwidt licensed under CC BY-NC-SA 2.0

Rattans are not a single taxonomic unit. Though they are all palms, at least 13 genera contain palms that exhibit this climbing habit. With over 600 species included in these groups, it goes without saying that there is a lot of variation on the theme. The largest rattan palms hail from the genus Calamus and all but one are native to Asia.

Many species of rattan have whip-like stems that would be easy to miss in a lush jungle. Be aware of your surroundings though, because these spikes are quite capable of ripping clothes and flesh to pieces. The rattans are like any other vine, sacrificing bulk for an easy ride into the light at the expense of whatever it climbs on. Indeed some get so big that they break their host tree. It is this searching, sprawling nature of the rattans that allow them to reach some impressive lengths. Some species of rattan have been reported with stems measuring over 500 feet!

Getting back to what I mentioned earlier about wicker furniture, rattans are a very important resource for the people of the jungles in which they grow. They offer food, building materials, shelter materials, an artistic medium, and a source of economic gain. In many areas, rattans are being heavily exploited as a result. This is bad for both the ecology of the forest and the locals who depend upon these species.

The global rattan trade is estimated at around $4 billion dollars. Because of this, rattans are harvested quite heavily and many are cut at too young of an age to re-sprout meaning little to no recruitment occurs in these areas. There is a lot of work being done by a few organizations to try to set up sustainable rattan markets in the regions that have been hit the hardest. More information can be found at sites like the World Wildlife Fund.

Photo Credits: [1] [2]

Further Reading: [1] [2] [3] [4]

The Plight of the African Violets

Photo by RobertoMM licensed under CC BY-SA 3.0

For many of us, African violets (Saintpaulia spp.) are some of the first houseplants we learned how to grow. They are not true violets (Violaceae), of course, but rather members of the family Gesneriaceae. Nonetheless, their compact rosettes of fuzzy leaves coupled with regular sprays of colorful flowers has made them a multi-million dollar staple of the horticultural industry. Unfortunately their numbers in captivity overshadow a bleak future for this genus in the wild. Many African violets are teetering on the brink of extinction.

The genus Saintpaulia is endemic to a small portion of east Africa, with a majority of species being found growing at various elevations throughout the Eastern Arc Mountains of Kenya and Tanzania. Most of the plants we grow at home are clones and hybrids of two species, S. ionantha and S. confusa. Collected in 1892, these two species were originally thought to be the same species, S. ionantha, until a prominent horticulturist noted that there are distinct differences in the seed capsules each produced. Since the 1890's, more species have been discovered.

Saintpaulia goetzeana

Exactly how many species comprise this genus is still up for some debate. Numbers range from as many as 20 to as few as 6. Much of the early work on describing various Saintpaulia species involved detailed descriptions of the density and direction of hairs on the leaves. More recent genetic work considers some of these early delineations to be tenuous at best, however, even these modern techniques have resolved surprisingly little when it comes to a species concept within this group.

Saintpaulia sp. in situ. Photo by TanzaniaPlantCollaboration licensed under CC BY-NC-SA 2.0

Though it can be risky to try and make generalizations about an entire genus, there are some commonalities when it comes to the habitats these plants prefer. Saintpaulia grow at a variety of elevations but most can be found growing on rocky outcrops. Most of them prefer growing in the shaded forest understory, hence they do so well in our (often) poorly lit homes. Their affinity for growing on rocks means that many species are most at home growing on rocks and cliffs near streams and waterfalls. The distribution of most Saintpaulia species is quite limited, with most only known from a small region of forest or even a single mountain. Its their limited geographic distribution that is cause for concern.

Saintpaulia ionantha subsp. grotei in situ.

Regardless of how many species there are, one fact is certain - many Saintpaulia risk extinction if nothing is done to save them. Again, populations of Saintpaulia species are often extremely isolated. Though more recent surveys have revealed that a handful of lowland species are more widespread than previously thought, mid to highland species are nonetheless quite restricted in their distribution. Habitat loss is the #1 threat facing Saintpaulia. Logging, both legal and illegal, and farming are causing the diverse tropical forests of eastern Africa to shrink more and more each year. As these forests disappear, so do Saintpaulia and all of the other organisms that call them home.

There is hope to be had though. The governments of Kenya and Tanzania have recognized that too much is being lost as their forests disappear. Stronger regulations on logging and farming have been put into place, however, enforcement continues to be an issue. Luckily for some Saintpaulia species, the type localities from which they were described are now located within protected areas. Protection coupled with inaccessibility may be exactly what some of these species need to survive. Also, thanks to the ease in which Saintpaulia are grown, ex situ conservation is proving to be a viable and valuable option for conserving at least some of the genetic legacy of this genus.

Saintpaulia intermedia [source]

It is so ironic to me that these plants can be so common in our homes and offices and yet so rare in the wild. Despite their popularity, few recognize the plight of this genus. My hope is that, in reading this, many of you will think about what you can do to protect the legacy of plants like these and so many others. Our planet and the species that call it home are doomed without habitat in which to live and reproduce. This is why land conservation is an absolute must. Consider donating to a land conservation organization today. Here are two worth your consideration:

The Nature Conservancy

The Rainforest Trust

Photo Credits: [1] [2] [3] [4] [5]

Further Reading: [1] [2] [3] [4] [5]

The Carnivorous Dewy Pine

Photo by David Eickhoff licensed under CC BY-NC-SA 2.0

The dewy pine is definitely not a pine, however, it is quite dewy. Known scientifically as Drosophyllum lusitanicum, this carnivore is odd in more ways than one. It is also growing more and more rare each year.

One of the strangest aspects of dewy pine ecology is its habitat preferences. Whereas most carnivorous plants enjoy growing in saturated soils or even floating in water, the dewy pine's preferred habitats dry up completely for a considerably portion of the year. Its entire distribution consists of scattered populations throughout the western Iberian Peninsula and northwest Morocco.

Photo by Javier martin licensed under CC BY-SA 3.0

Its ability to thrive in such xeric conditions is a bit of a conundrum. Plants stay green throughout the year and produce copious amounts of sticky mucilage as a means of catching prey. During the summer months, both air and soil temperatures can skyrocket to well over 100°F (37 °C). Though they possess a rather robust rooting system, dewy pines don't appear to produce much in the way of fine roots. Because of this, any ground water presence deeper in the soil is out of their reach. How then do these plants manage to function throughout the driest parts of the year?

During the hottest months, the only regular supply of water comes in the form of dew. Throughout the night and into early morning, temperatures cool enough for water to condense out of air. Dew covers anything with enough surface area to promote condensation. Thanks to all of those sticky glands on its leaves, the dewy pine possesses plenty of surface area for dew to collect. It is believed that, coupled with the rather porous cuticle of the surface of its leaves, the dewy pine is able to obtain water and reduce evapotranspiration enough to keep itself going throughout the hottest months. 

Dewy pine leaves unfurl like fern fiddle heads as they grow. Photo by Mark Freeth licensed under CC BY 2.0

As you have probably guessed at this point, those dewy leaves do more than photosynthesize and collect water. They also capture prey. Carnivory in this species evolved in response to the extremely poor conditions of their native soils. Nutrients and minerals are extremely low, thus selecting for species that can acquire these necessities via other means. Each dewy pine leaf is covered in two types of glands: stalked glands that produce sticky mucilage, and sessile glands that secrete digestive enzymes and absorb nutrients.

Their ability to capture insects far larger than one would expect is quite remarkable. The more an insect struggles, the more it becomes ensnared. The strength of the dewy pines mucilage likely stems from the fact that the leaves do not move like those of sundews (Drosera spp.). Once an insect is stuck, there is not much hope for its survival. Living in an environment as extreme as this, the dewy pine takes no chances.

Photo by Strombus72 licensed under CC BY-SA 4.0

The taxonomic affinity of the dewy pine has been a source of confusion as well. Because of its obvious similarity to the sundews, the dewy pine has long been considered a member of the family Droseraceae. However, although recent genetic work does suggest a distant relationship with Droseraceae and Nepenthaceae, experts now believe that the dewy pine is unique enough to warrant its own family. Thus, it is now the sole species of the family Drosophyllaceae.

Sadly, the dewy pine is losing ground fast. From industrialization and farming to fire suppression, dewy pines are running out of habitat. It is odd to think of a plant capable of living in such extreme conditions as being overly sensitive but that is the conundrum faced by more plants than just the dewy pine. Without regular levels of intermediate disturbance that clear the landscape of vegetation, plants like the dewy pine quickly get outcompeted by more aggressive plant species. Its the fact that dewy pine can live in such hostile environments that, historically, has kept its populations alive and well.

Photo by Javier martin licensed under Public Domain

What's more, it appears that dewy pines have trouble getting their seeds into new habitats. Low seed dispersal ability means populations can be cut off from suitable habitats that are only modest distances away. Without a helping hand, small, localized populations can disappear alarmingly fast. The good news is, conservationists are working hard on identifying what must be done to ensure the dewy pine is around for future generations to enjoy.

Changes in land use practices, prescribed fires, wild land conservation, and incentives for cattle farmers to adopt more traditional rather than industrial grazing practices may turn the table on dewy pine extinction. Additionally, dewy pines have become a sort of horticultural oddity over the last decade or so. As dedicated growers perfect germination and growing techniques, ex situ conservation can help maintain stocks of genetic material around the globe.

Photo Credits: [1] [2] [3] [4] [5]

Further Reading: [1] [2] [3] [4]

Saving One of North America's Rarest Shrubs

Photo by Stan Shebs licensed under CC BY-SA 3.0

The chance to save a species from certain extinction cannot be wasted. When the opportunity presents itself, I believe it is our duty to do so. Back in 2010, such an opportunity presented itself to the state of California and what follows is a heroic demonstration of the lengths dedicated individuals will go to protect biodiversity. Thought to be extinct for 60 years, the Franciscan manzanita (Arctostaphylos franciscana) has been given a second chance at life on this planet.

California is known the world over for its staggering biodiversity. Thanks to a multitude of factors that include wide variations in soil and climate types, California boasts an amazing variety of plant life. Some of the most Californian of these plants belong to a group of shrubs and trees collectively referred to as 'manzanitas.' These plants are members of the genus Arctostaphylos, which hails from the family Ericaceae, and sport wonderful red bark, small green leaves, and lovely bell-shaped flowers. Of the approximately 105 species, subspecies, and varieties of manzanita known to science, 95 of them can be found growing in California.

It has been suggested that manzanitas as a whole are a relatively recent taxon, having arisen sometime during the Middle Miocene. This fact complicates their taxonomy a bit because such a rapid radiation has led manzanita authorities to recognize a multitude of subspecies and varieties. In California, there are also many endemic species that owe their existence in part to the state's complicated geologic history. Some of these manzanitas are exceedingly rare, having only been found growing in one or a few locations. Sadly, untold species were probably lost as California was settled and human development cleared the land. 

Such was the case for the Franciscan manzanita. Its discovery dates back to the late 1800's. California botanist and manzanita expert, Alice Eastwood, originally collected this plant on serpentine soils around the San Francisco Bay Area. In the years following, the growing human population began putting lots of pressure on the surrounding landscape.

Photo by Daderot (public domain)

Botanists like Eastwood recognized this and went to work doing what they could to save specimens from the onslaught of bulldozers. Luckily, the Franciscan manzanita was one such species. A few individuals were dug up, rooted, and their progeny were distributed to various botanical gardens. By the 1940's, the last known wild population of Franciscan manzanita were torn up and replaced by the unending tide of human expansion into the Bay Area.

It was apparent that the Franciscan manzanita was gone for good. Nothing was left of its original populations outside of botanical gardens. It was officially declared extinct in the wild. Decades went by without much thought for this plant outside of a few botanical circles. All of that changed in 2009.

It was in 2009 when a project began to replace a stretch of roadway called Doyle Drive. It was a massive project and a lot of effort was invested to remove the resident vegetation from the site before work could start in earnest. Native vegetation was salvaged to be used in restoration projects but most of the clearing involved the removal of aggressive roadside trees. A chipper was brought in to turn the trees into wood chips. Thanks to a bit of serendipity, a single area of vegetation bounded on all sides by busy highway was spared from wood chip piles. Apparently the only reason for this was because a patrol car had been parked there during the chipping operation.

Cleared of tall, weedy trees, this small island of vegetation had become visible by road for the first time in decades. That fall, a botanist by the name of Daniel Gluesenkamp was driving by the construction site when he noticed an odd looking shrub growing there. Luckily, he knew enough about manzanitas to know something was different about this shrub. Returning to the site with fellow botanists, Gluesenkamp and others confirmed that this odd shrubby manzanita was in fact the sole surviving wild Franciscan manzanita. Needless to say, this caused a bit of a stir among conservationists.

The shrub had obviously been growing in that little island of serpentine soils for quite some time. The surrounding vegetation had effectively concealed its presence from the hustle and bustle of commuters that crisscross this section of on and off ramps every day. Oddly enough, this single plant likely owes its entire existence to the disturbance that created the highway in the first place. Manzanitas lay down a persistent seed bank year after year and those seeds can remain dormant until disturbance, usually fire but in this case road construction, awakens them from their slumber. It is likely that road crews had originally disturbed the serpentine soils just enough that this single Franciscan manzanita was able to germinate and survive.

The rediscovery of the last wild Franciscan manzanita was bitter sweet. On the one hand, a species thought extinct for 60 years had been rediscovered. On the other hand, this single individual was extremely stressed by years of noxious car exhaust and now, the sudden influx of sunlight due to the removal of the trees that once sheltered it. What's more, this small island of vegetation was doomed to destruction due to current highway construction. It quickly became apparent that if this plant had any chance of survival, something drastic had to be done.

Many possible rescue scenarios were considered, from cloning the plant to moving bits of it into botanical gardens. In the end, the most heroic option was decided on - this single Franciscan manzanita was going to be relocated to a managed natural area with a similar soil composition and microclimate.

Moving an established shrub is not easy, especially when that particular individual is already stressed to the max. As such, numerous safeguards were enacted to preserve the genetic legacy of this remaining wild individual just in case it did not survive the ordeal. Stem cuttings were taken so that they could be rooted and cloned in a lab. Rooted branches were cut and taken to greenhouses to be grown up to self-sustaining individuals. Numerous seeds were collected from the surprising amount of ripe fruits present on the shrub that year. Finally, soil containing years of this Franciscan manzanita's seedbank as well as the microbial community associated with the roots, were collected and stored to help in future reintroduction efforts.

Finally, the day came when the plant was to be dug up and moved. Trenches were dug around the root mass and a dozen metal pipes were driven into the soil 2 feet below the plant so that the shrub could safely be separated from the soil in which it had been growing all its life. These pipes were then bolted to I-beams and a crane was used to hoist the manzanita up and out of the precarious spot that nurtured it in secret for all those years.

Upon arriving at its new home, experts left nothing to chance. The shrub was monitored daily for the first ten days of its arrival followed by continued weekly visits after that. As anyone that gardens knows, new plantings must be babied a bit before they become established.  For over a year, this single shrub was sheltered from direct sun, pruned of any dead and sickly branches, and carefully weeded to minimize competition. Amazingly, thanks to the coordinated effort of conservationists, the state of California, and road crews, this single individual lives on in the wild.

Of course, one single individual is not enough to save this species from extinction. At current, cuttings, and seeds provide a great starting place for further reintroduction efforts. Similarly, and most importantly, a bit of foresight on the part of a handful of dedicated botanists nearly a century ago means that the presence of several unique genetic lines of this species living in botanical gardens means that at least some genetic variability can be introduced into the restoration efforts of the Franciscan manzanita.

In an ideal world, conservation would never have to start with a single remaining individual. As we all know, however, this is not an ideal world. Still, this story provides us with inspiration and a sense of hope that if we can work together, amazing things can be done to preserve and restore at least some of what has been lost. The Franciscan manzanita is but one species that desperately needs our help an attention. It is a poignant reminder to never give up and to keep working hard on protecting and restoring biodiversity.

Photo Credits: [1] [2] [3] [4]

Further Reading: [1] [2] [3] [4]

Prescribed Fire On An Illinois Prairie

Prairies are fire adapted ecosystems. For far too long, fires were sequestered. Today, more and more communities are coming around to the fact that fire can be used as a tool to bring life back to these endangered ecosystems. In this video, we get hands on experience with fire as a prairie restoration tool.

Producer, Editor, Camera: Grant Czadzeck (http://www.grantczadzeck.com)

Music by
Artist: Stranger In My Town
Track: Terra
https://strangerinmytown.bandcamp.com/

Daffodil Insights

Photo by Amanda Slater licensed under CC BY-SA 2.0

Daffodils seem to be everywhere. Their horticultural popularity means that, for many of us, these plants are among the first flowers we see each spring. Daffodils are so commonplace that it's as if they evolved to live in our gardens and nowhere else. Indeed, daffodils have had a long, long history with human civilization, so much so that it is hard to say when our species first started to cohabitate. Our familiarity with these plants belies an intriguing natural history. What follows is a brief overview of the world of daffodils. 

If you are like me, then you may have gone through most of your life not noticing much difference between garden variety daffodils. Though many of us will be familiar with only a handful of daffodil species and cultivars, these introductions barely scratch the surface. One may be surprised to learn that as of 2008, more than 28,000 daffodil varieties have been named and that number continues to grow each and every year. Even outside of the garden, there is some serious debate over the number of daffodil species, much of this having to do with what constitutes a species in this group.

Narcissus poeticus

As I write this, all daffodils fall under the genus Narcissus. Estimates as to the number of species within Narcissus range from as few as 50 to as many as 80. The genus itself sits within the family Amaryllidaceae and is believed to have originated somewhere between the late Oligocene and early Miocene, some 18 to 30 million years ago. Despite its current global distribution, Narcissus are largely Mediterranean plants, with peak diversity occurring on the Iberian Peninsula. However, thanks to the aforementioned long and complicated history in cultivation, it has become quite difficult to understand the full range of diversity in form and habitat of many species. To understand this, we first need to understand a bit about their reproductive habits.

Much of the evolution of Narcissus seems to center around floral morphology and geographic isolation. More specifically, the length of the floral tube or "corona" and the position of the sexual organs within, dictates just who can effectively pollinate these plants. The corona itself is not made up of petals or sepals but instead, its tube-like appearance is due to a fusion of the stamens into the famous trumpet-like tube we know and love.

Variation in corona shape and size has led to the evolution of three major pollination strategies within this genus. The first form is the daffodil form, whose stigma is situated at the mouth of the corolla, well beyond the 6 anthers. This form is largely pollinated by larger bees. The second form is the paperwhite form, whose stigma is situated more closely to or completely below the anthers at the mouth of the corona. This form is largely pollinated by various Lepidoptera as well as long tongued bees and flies. The third form is the triandrus form, which exhibits three distinct variations on stigma and anther length, all of which are situated deep within the long, narrow corona. The pendant presentation of the flowers in this group is thought to restrict various butterflies and moths from entering the flower in favor of bees.

Narcissus tazetta. Photo by Fanghong licensed under CC BY-SA 3.0

The variations on these themes has led to much reproductive isolation among various Narcissus populations. Plants that enable one type of pollinator usually do so at the exclusion of others. Reproductive isolation plus geographic isolation brought on by differences in soil types, habitat types, and altitudinal preferences is thought to have led to a rapid radiation of these plants across the Mediterranean. All of this has gotten extremely complicated ever since humans first took a fancy to these bulbs.

Narcissus cyclamineus. Photo by Francine Riez licensed under CC BY-SA 3.0

Reproductive isolation is not perfect in these plants and natural hybrid zones do exist where the ranges of two species overlap. However, hybridization is made much easier with the helping hand of humans. Whether via landscape disturbance or direct intervention, human activity has caused an uptick in Narcissus hybridization. For centuries, we have been mixing these plants and moving them around with little to no record as to where they originated. What's more, populations frequently thought of as native are actually nothing more than naturalized individuals from ancient, long-forgotten introductions. For instance, Narcissus populations in places like China, Japan, and even Great Britain originated in this manner.

All of this mixing, matching, and hybridizing lends to some serious difficulty in delineating species boundaries. It would totally be within the bounds of reason to ask if some of the what we think of as species represent true species or simply geographic varieties on the path to further speciation. This, however, is largely speculative and will require much deeper dives into Narcissus phylogenetics.

Narcissus triandrus. Photo by Dave Gough licensed under CC BY 2.0

Despite all of the confusion surrounding accurate Narcissus taxonomy, there are in fact plenty of true species worth getting to know. These range in form and habit far more than one would expect from horticulture. There are large Narcissus and small Narcissus. There are Narcissus with yellow flowers and Narcissus with white flowers. Some species produce upright flowers and some produce pendant flowers. There are even a handful of fall-blooming Narcissus. The variety of this genus is staggering if you are not prepared for it.

Narcissus viridiflorus - a green, fall-blooming daffodil. Photo by A. Barra licensed under CC BY 3.0

After pollination, the various Narcissus employ a seed dispersal strategy that doesn't get talked about enough in reference to this group. Attached to each hard, black seed are fatty structures known as eliasomes. Eliasomes attract ants. Like many spring flowering plant species around the globe, Narcissus utilize ants as seed dispersers. Ants pick up the seeds and bring them back to their nests. They go about removing the eliasomes and then discard the seed. The seed, safely tucked away in a nutrient-rich ant midden, has a much higher chance of germination and survival than if things were left up to simple chance. It remains to be seen whether or not Narcissus obtain similar seed dispersal benefits from ants outside of their native range. Certainly Narcissus populations persist and naturalize readily, however, I am not aware if ants have any part in the matter.

The endangered Narcissus alcaracensis. Photo by José Luis López González licensed under CC BY-SA 4.0

Despite their popularity in the garden, many Narcissus are having a hard go of it in the wild. Habitat destruction, climate change, and rampant collecting of wild bulbs are having serious impacts on Narcissus numbers. The IUCN considered at least 5 species to be endangered and a handful of some of the smaller species already thought to be extinct in the wild. In response to some of these issues, protected areas have been established that encompass at least some of the healthy populations that remain for some of these species.

If you are anything like me, you have ignored Narcissus for far too long. Sure, they aren't native to the continent on which I live, and sure, they are one of the most commonly used plants in a garden setting, but every species has a story to tell. I hope that, armed with this new knowledge, you at least take a second look at the Narcissus popping up around your neighborhood. More importantly, I hope this introduction makes you appreciate their wild origins and the fact that we still have much to learn about these plants. I have barely scratched the surface of this genus and there is more more information out there worth perusing. Finally, I hope we can do better for the wild progenitors of our favorite garden plants. They need all the help they can get and unless we start speaking up and working to preserve wild spaces, all that will remain are what we have in our gardens and that is not a future I want to be a part of.

Photo Credits: [1] [2] [3] [4] [5] [6] [7]

Further Reading: [1] [2] [3] [4] [5] [6] [7] [8] [9]

The Other Pawpaws

Asimina tetramera Photo by Bob Peterson licensed under CC BY-SA 2.0

The pawpaw (Asimina triloba) has been called "America's forgotten fruit." Once popular among Native Americans and settlers alike, it fell out of the public eye until quite recently. If one considers the pawpaw "forgotten" then its relatives have been straight up ignored. Indeed, the pawpaw shares the North American continent with 10 other Asimina species. 

Asimina angustifolia Photo by Mason Brock

The genus Asimina belongs to a family of plants called the custard apple family - Annonaceae. It is a large family that mostly resides in the tropics. In fact, the genus Asimina is the only group to occur outside of the tropics. Though A. triloba finds itself growing as far north as Canada, the other species within this genus are confined to southeastern North America in coastal plain communities. 

Asimina parviflora Photo by Mason Brock

As I mentioned above, there are 10 other species in the genus and at least one naturally occurring hybrid. For the most part, they all prefer to grow where regular fires keep competing vegetation at bay. They are rather small in stature, usually growing as shrubs or small, spindly trees. They can be pretty inconspicuous until it comes time to flower.

Asimina obovata Photo by Homer Edward Price licensed under CC BY 2.0

The flowers of the various Asimina species are relatively large and range in color from bright white to deep red, though the most common flower color seems to be creamy white. The flowers themselves give off strange odors that have been affectionately likened to fermenting fruit and rotting meat. Of course, these odors attract pollinators. Asimina aren't much of a hit with bees or butterflies. Instead, they are mainly visited by blowflies and beetles. 

As is typical of the family, all of the Asimina produce relatively large fruits chock full of hard seeds. Seed dispersal for the smaller species is generally accomplished through the help of mammals like foxes, coyotes, raccoons, opossums, and even reptiles such as the gopher tortoise. Because the coastal plain of North America is a fire-prone ecosystem, most of the Asimina are well adapted to cope with its presence. In fact, most require it to keep their habitat open and free of too much competition. At least one species, A. tetramera, is considered endangered in large part due to fire sequestration.

Asimina reticulata Photo by Bob Peterson licensed under CC BY-SA 2.0

All of the 11 or so Asimina species are host plants for the zebra swallowtail butterfly (Eurytides marcellus) and the pawpaw sphinx moth (Dolba hyloeus). The specialization of these two insects and few others has to do with the fact that all Asimina produce compounds called acetogenins, which act as insecticides. As such, only a small handful of insects have adapted to be able to tolerate these toxic compounds. 

Asimina tetramera

Sadly, like all other denizens of America's coastal plain forest, habitat destruction is taking its toll on Asimina numbers. As mentioned above, at least one species (A. tetramera) is considered endangered. We desperately need to protect these forest habitats. Please support a local land conservation organization like the Partnership For Southern Forestland Conservation today!

LISTEN TO AN INTERVIEW ALL ABOUT PAWPAW FLOWER SCENTS

See a list of the Asimina of North America here: [1] 

Further Reading: [1] [2] [3] [4] [5]