I live for moments like this. The only downside to that is I can never really predict when they are going to happen. There I was driving up a mountain road in search of a handful of other plant species related to my research. The road was narrow and there was a steep bank on the drivers side. The Southern Appalachian Mountains are brimming with botanical diversity. As such, it can be hard to tease out individual plants, especially while driving. This is why having a refined search image comes in handy.
I was rounding a bend in the road when something out my window caught my eye. My mind went racing and it wasn't long before a suspicion crept into my head. If I was right, this was an opportunity I was not going to miss. I found the nearest pull off, parked the truck, and ran back down the road. I am so happy that I decided to trust my instincts. There in front of me was a small population of whorled pogonia orchids (Isotria verticillata).
It was like being in the presence of a celebrity that I had been stalking for years. This was an orchid I have been dying to see. The harder I looked the more I saw. I had to sit down. Here in front of me was a species of orchid that isn't seen by many. In fact, entire populations of these species can go unseen for decades until they have enough energy to flower.
Flowering in this species is said to be quite erratic. Because they live in shaded environments, building up the energy needed to reproduce can be difficult. Like all orchids, the whorled pogonia relies on an obligate relationship with mycorrhizal fungi to supply the nutrients it needs. In return, the orchids provide fungi with carbohydrates. The problem with erratic flowering, however, is that it makes reproduction difficult. Rarely are two populations flowering at the same time and in close enough proximity for successful cross pollination. More often, these orchids will self fertilize, which can lead to high rates of inbreeding.
Large bees are the main pollinators of the whorled pogonia. The flowers themselves are reported to produce a feint odor reminiscent of Vanilla. This is interesting to note because in the greater scheme of orchid phylogenetics, this species is placed in the Vanilla subfamily, although such distinctions can get muddled quickly. Regardless, simply being in the presence of this orchid was enough to give me goosebumps. It is a shame that such a species is being lost throughout much of its range.
Further Reading:
http://bit.ly/1ssBmdF
http://bit.ly/1WEmZzm
Spring Surprise on the Tallgrass Prairie
I have no frame of reference for spring on the tallgrass prairie. Everything is new to me. It is amazing to see what starts to come up before all of the grasses wake up and make things a lot harder to find. Diminutive herbs take advantage of sunlight while they can. What I also like is how well certain species stand out against a backdrop of last year's dry stems. This is how I was able to find wild hyacinth (Camassia scilloides).
The first time I laid eyes on this species, I was actually looking for birds. The spot I was in is known for harboring pheasants. I could hear the males calling but I was having a hard time locating these colorful birds. As I scanned the prairie for shots of color, something else caught my eye. From where I was standing, it looked like a green stick covered in foam. I couldn't quite make out enough detail. I knew it had to be a plant but the search imagine simply wasn't there. I had to investigate.
Gingerly I tip toed out into the grasses trying to avoid stepping on emerging vegetation. Luckily some deer had already beat a path pretty close to where this mystery plant was growing. When I was only a few yards away I quickly realized what I was seeing. It was a small patch of wild hyacinth. From a distance it was hard to resolve the outline of the tightly packed flowers. From up close, however, it is one of the most stunning spring displays I have ever seen.
They were covered in ants. As it turns out, these flowers produce copious amounts of nectar. Whereas ants offer nothing in the way of pollination, myriad other insects like flies, bees, butterflies, and wasps visit these blooms in search of a sweet, energy-rich meal. This plant seems to have no trouble getting pollinated. This is a spring species, emerging from an underground bulb not unlike the hyacinths you buy at nurseries. It has slender, grass-like foliage that isn't always apparent mixed in with all of the other vegetation.
I was a little surprised that such an obvious plant could exist unharmed so near a deer path until I did some research. Like many of its relatives, wild hyacinth is quite toxic to mammals. As such, the deer were smart to pass it up. After years of seeing nothing but its introduced Asian relatives, I was quite happy to be meeting an eastern species native to North America.
Further Reading:
North America's Native Peonies
Brown's peony (Paeonia brownii). Photo by Mathesont licensed under CC BY-NC 2.0
Foliage of Brown's peony (Paeonia brownii). Photo by jacki-dee licensed under CC BY-NC-ND 2.0
Brown's peony (Paeonia brownii). Photo by Jim Morefield licensed under CC BY-SA 2.0
Whereas most species of peony are Eurasian in decent, there are two species of peony that are native to North America. Brown's peony (Paeonia brownii) inhabits high elevation regions of most of northwestern North America. The California peony (Paeonia californica) has a much narrower range, limited to southwestern California. Some feel it should be considered a subspecies of P. brownii. While not as showy as their Eurasian cousins, they are nonetheless quite interesting plants!
California peony (Paeonia californica). Photo by Dagmar Collins licensed under CC BY-NC-ND 2.0
California peony (Paeonia californica). Photo by Justin Meissen licensed under CC BY-SA 2.0
California peony (Paeonia californica). Photo by Teddy Llovet licensed under CC BY 2.0
Photo Credits: [1] [2] [3] [4] [5] [6]
Further Reading:
http://plants.usda.gov/core/profile?symbol=PACA2
On Peonies and Ants
Photo by George Vopal licensed under CC BY 2.0
It is just about that time when peony buds burst forth and put on their late spring display. My mother loves her peonies and she gets very excited every year when they bloom. It's adorable. However, she has always been disgusted by the amount of ants the peonies attract. Indeed, many people all over the internet seem to feel the same way. Growing up, I always wondered why the ants seemed to swarm all over peony buds, so I decided to look into it a little deeper.
There are many sources out there that claim that peonies need ants in order to bloom. To me, this seems very maladaptive on the part of the peony. The genus Paeonia is represented in Asia, Southern Europe and parts of western North America. I am going to assume that the ant/peony relationship didn't start in the garden so it's roots have to be somewhere in the evolutionary history of the plant. What sense does it make for a plant to produce flower buds that excrete sticky sugars that keep them from opening until something cleans the sugars off? In fact, despite anecdotal reports, peony buds will open without ants. So then why does the plant bother to produce sugars that attract ants?
Interestingly enough, despite a good amount of searching, there is not a lot of research done on this subject but the answer to this question can come from looking at how ants interact with other plants and animals. Many plant species have special glands on their stems that produce sugary secretions which attract ants. It's not just plants either. Insects such as aphids and leafhoppers famously excrete honeydew that ants can't resist. In each of these cases, organisms are using the ants' natural tendency to guard a food source. The ants will viciously attack anything that threatens this easy meal.
It would seem to me that the peonies are doing just that with their flower buds. By secreting a sugary substance during their development, the plant are likely recruiting ants to protect the flowers, which for angiosperms, are the most precious part of the plant. It takes a lot out of a plant to flower and the threat of herbivory is ever present. If an insect tries to take a bite out of a bud, the ants quickly swarm and drive it off. It's a win-win situation. The ants get an easy, high-energy food source and the plant suffers less damage to its reproductive organs.
The scary part to me in researching all of this is plethora of information out there on how to get rid of the ants. People go through chemical after chemical to rid their peonies of ants when, in reality, the ants are some of the best friends a peony could have! So leave those ants alone and enjoy the free pest removal services they provide every spring!
Photo Credit: [1]
Further Reading:
http://www.youtube.com/watch?v=Gnm2nV_nwOk
Enigmatic Neviusia
Photo by Philip Bouchard licensed under CC BY-NC-ND 2.0
Neviusia. The first time I heard it mentioned I was certain the conversation had switched from reality to the world of Harry Potter. I was wrong. The name belongs to a genus of plants that are totally real. What's more, the natural history of this small group is absolutely fascinating.
The genus Neviusia is comprised of two extant species. N. alabamensis is endemic to a small region of the southeastern United States around northwest Georgia and the Ozark Mountains. Its cousin, N. cliftonii, was discovered in 1992 and is endemic to a small area around "Lake" Shasta in California. Fewer than 20 populations have been found and of them, six were flooded to create "Lake" Shasta. It would seem very strange that both species in this genus are not only endemic to extremely localized regions but also completely disjunct from one another. This is only the beginning.
Whereas fruits have been described for N. cliftonii, none have been reported in N. alabamensis. Ever. Thanks to genetic analysis, populations of both plants are thought to be entirely clonal. High rates of pollen sterility are to blame. Why this is the case is hard to say. It is thought that the genus Neviusia is a relict of the early Cenozoic. Fossil evidence from British Columbia suggest that this genus was once more diverse and more wide spread, having gradually declined to its current limited distribution. The Pleistocene was likely the last straw for these plants, being corralled into small refugia of suitable habitat by the glaciers. Lack of seed production (perhaps due to genetic drift) meant that these two species were to never recolonize their former range. At least not without help...
Since their discovery, these two species have garnered some attention. Like Franklinia, Neviusia have become a sort of horticultural curiosity and have since been out-planted in a variety of locations. My first and only encounter with Neviusia occurred in a conservation garden. Despite their popularity among researchers and gardeners alike, it is unlikely that Neviusia will ever reclaim even a fraction of their former glory. Instead, they remain as endemic reminders of a bygone era. Despite their limited range I think it is important to remember just how long they have survived in North America. After millions of years of survival and persistence, their biggest threat is now us.
Photo Credit: Philip Bouchard (http://bit.ly/1WpElzX)
Further Reading:
http://bit.ly/1NqFdlq
http://bit.ly/1ZFEa1G
http://bit.ly/1UT2WfF
http://bit.ly/24OshNM
http://bit.ly/1TFblOd
http://bit.ly/1rWecMq
Dwarf Larkspur
There are certain genera that I almost always encounter in a garden setting. These are usually gaudy cultivars from other continents. This is especially true for Delphiniums. Since I moved back east, the only Delphiniums I see are garden varieties. All of that changed when I moved to Illinois. During one of my first day hikes in the Midwest, I had the pleasure of meeting a Delphinium I had never met before. What's more, I managed to stumble upon a patch of forest that boasted a rather large population. The species in question is the dwarf larkspur (Delphinium tricorne) and it is a plant worth knowing.
Dwarf larkspur is native to a good chunk of the eastern United States, only absent from the northeastern and southeastern portions. It is a spring bloomer, flowering for about three weeks in late spring. The inflorescence this plant produces is stunning to say the least. If you're lucky enough to find yourself surrounded by these plants like I was, its as if the entire forest floor is awash in a sea of deep purple.
The flowers can only be pollinated by queen bumblebees and hummingbirds. Whereas other insects will visit the flowers, the morphology is such that they are not effective pollinators. By the beginning of summer, the plants will have produced their seeds. At this time, however, the embryo within is not yet mature. It will not mature until the coming fall. Dwarf larkspur embryos do not begin to grow until temperatures have dropped to around 5 °C (41 °F). Then and only then will the seeds be ready to germinate, all in time for the arrival of spring.
Like nearly all members of the buttercup family, the dwarf larkspur produces toxic alkaloids. Because of this, few herbivores will chance a nibble. Unfortunately for Delphiniums across North America, this fact has earned them a rather negative reputation among livestock owners. Nonetheless, these plants are wonderful and important ecological components wherever they are native. What's more, dwarf larkspur is growing in popularity among native gardeners looking to add some color to shaded portions of their landscape.
Further Reading: [1] [2]
Beautiful Bitterroot
During the summer of 2011, I entered into a small love affair with a wonderful little succulent rosette. I would see them scattered about the sagebrush. They always brightened my day. They seemed so foreign compared to the northeastern flora I was used to. The cylindrical leaves were tightly packed and hugged the ground, no doubt to get away from the constant winds that blow across the terrain. It didn't take long to learn its name. The flora I was using told me that these plants were none other than Lewisia rediviva, more commonly known as bitterroot.
Bitterroot is native to much of North America west of the Rockies. It can be found growing at elevations ranging from 2,500 feet to over 10,000 feet. This is one hardy little plant. Its position taxonomically speaking has changed a bit as of late. This species was once placed in the family Portulacaceae but recent analyses now suggest it in a new family - Montiaceae.
The rosette of leaves are produced from a cylindrical taproot in late summer. They will remain green throughout the fall and into the harsh winter, insulated under the snow. This allows the plant to get a head start on photosynthesis come spring. As the snow slowly melts away, bitterroot begins producing flower buds.
As the flower buds mature, the leaves begin to senesce. Very often you will find flowers and no leaves, which may lead some to believe they have witnessed two different plants. Either way, the flowers are quite the spectacle. Blooming time varies depending on latitude and elevation but between the months of April and June, bitterroot enters reproductive mode. If you're a fan of big flowers on small plants, then this species is right up your alley. The 2 inch flowers are borne flush with the ground and vary in color from stark white to bright pink. Their display is made all the more magnificent by the fact that bitterroot is often found growing in bare soil, devoid of other flowering forbs.
Further Reading:
http://on.doi.gov/1QVDFKK
http://1.usa.gov/1Wim1JC
An Awesome Ophioglossum
Sometimes I wonder how I must look to casual hikers. There I was sprawled out next to the trail, focusing all of my attention on a nondescript patch of leaves poking up where the trail ended and the grass began. This wasn't just any sort of leaf though. The object of my attention was an ancient member of the fern lineage commonly referred to as an adder's tongue. I will gladly look like a weirdo if it means spending time in the presence of such a cool plant.
To be more specific, the species in question here is the southern adder's tongue (Ophioglossum pychnostichum). Though not overtly showy like its more derived cousins, this little fern is nonetheless quite the show stopper if you know what you're looking for. It is generally considered a grassland associate and is most often encountered growing alongside trails. I'm not sure if this has to do with some disturbance related factor or the fact that even modestly sized plants can overshadow it.
Regardless, I felt very fortunate to be in the presence of at least one reproductive individual. For much of its life, the southern adder's tongue exists as a gametophyte followed by an underground fleshy rhizome. It can exist in this state for years, being nourished solely by an obligate association with mycorrhizal fungi. When a certain energy threshold is reached, individuals will then produce a single, sterile leaf. This can go on for season after season as the fern slowly stores away nutrients. When enough energy has been stored, mature individuals can then produce a spore bearing structure called a "sporophyll."
Despite its common name, this particular species distributed throughout the Northern Hemisphere. It can be found growing in North America, Europe, and temperate Asia. Still, since it is such a nondescript little plant, it rarely gets the attention it deserves when it comes to conservation. It is of conservation concern in at least a handful of states. Because its lifecycle can be hard to predict, growing some years and not others, accurate estimates of population size and health can be difficult.
The family to which is belongs is quite interesting on a genetic level as well. Ophioglossaceae is known for having staggeringly large chromosome counts. One species in particular - Ophioglossum reticulatum - boasts a whopping set of 1260 chromosomes. To put that into perspective, we humans only have 46. I guess thats what can happen to a genome that has had millions upon millions of years of natural selection working upon it.
Further Reading:
The Anachronistic Kentucky Coffee Tree
Photo by Flora Urbana
To see a Kentucky coffee tree (Gymnocladus dioicus) in the wild is a rare event. Each year your chances of doing so are diminishing. This interesting and beautiful legume is quite rare, growing in small scattered populations throughout eastern and Midwestern North America. Presettlement records hint that its rarity in nature is not necessarily a recent phenomenon either. It seems that, at least since humans have been paying attention, this tree has always been scarce.
Despite its rarity in the wild, the Kentucky coffee tree has gained a lot of popularity as a landscape tree. It is an attractive species with contorted branching and large, airy leaves. It's about this time of year when folks start wondering if they have killed the new tree they planted last fall. I often hear complaints from folks new to this species that their trees must have lost their buds over the winter. The reason for this lies in its generic name. "Gymnocladus" is Greek for "naked branch." The leaf buds are not exposed like they are in other tree species. Instead, they are imbedded within the twigs, hidden under a hairy ring of bark. Kentucky coffee tree does not leaf out until late spring, well after most other trees have broken dormancy.
In the wild, Kentucky coffee tree can be found growing on floodplains and, very occasionally, scattered through upland habitats. As such, water has been invoked as the only known dispersal agent. This is a strange mechanism to call on as nothing about this tree (other than its current habitat) suggests adaptations for water dispersal. Its seed pods are quite heavy, chock full sweet pulp, and don't float very well. What's more, the pods often remain on the tree all winter and the large seeds within require ample scarification before they will germinate. They are toxic to boot.
Even more perplexing is just how well this species does when planted outside of floodplains. It seems equally at home growing in a yard or along the sidewalk as it does on a floodplain. Taken together, all of these clues seem to suggest that the Kentucky coffee tree is missing something. Perhaps it is missing a preferred seed disperser?
The megafaunal dispersal syndrome has become a sexy topic in ecology. Essentially it posits that North America was once home to a bewildering array of large mammals that flourished leading up to the end of the Pleistocene. With that many large animals haunting this once wild continent, many have suggested that North American vegetation evolved to cope with and even exploit their presence. Certainly we see this happen on a smaller scale with things like birds and small mammals. We see it on a much larger scale with animals like elephants and rhinos in Africa and Asia. Could it be that when the Pleistocene megafuna went extinct in North America, the plant species they dispersed suffered a huge ecological blow?
The limited range of species like the Kentucky coffee tree would certainly seem to suggest so. Though it is a hard theory to test, the fruits of this tree seem adapted to something much more specific than running water. The large pod, the sweet pulp, and the hard seeds would suggest that the Kentucky coffee tree requires a larger mammalian herbivore to eat, scarify, and pass its seeds. No animal native to this continent today does the trick effectively. Most animals avoid the seeds entirely, which is likely due to their toxicity. Sure, the occasional seed germinates successfully, however, based on its limited natural range, the fecundity of the Kentucky coffee tree has been diminished.
Photo Credit: Roger Latourwww.floraurbana.blogspot.ca
Further Reading:
Three Cheers for Fungus Gnats!
Photo by Canyon Country Discovery Center licensed under CC BY-ND 2.0
Bees, butterflies, bats, and birds... Most of us are all too familiar (and thankful) for their roles as plant pollinators. However, there are some unsung heroes of this niche and one of them are the often overlooked fungus gnats.
Pollinators, for good reason, are one of the largest selective pressures on flower evolution. As flowers evolve to cater to a specific kind of pollinator, be it a bird, a bee, or even fungus gnats, we refer to it as a pollinator syndrome. I have been enchanted by the flowers of the genus Mitella ever since I stumbled across them. As you can see in the picture, they are generally saucer shaped and have snowflake-like appendages protruding from their rim. I wondered, what kind of pollinator syndrome would produce such delicate beauty?
A quick search in the literature turned up a paper from a team of botanists based out of the University of Idaho. The paper outlines work done across a wide range of genera in the Saxifragaceae family. They looked at flower morphology and, through hours of field observation, found a common theme in many species. Those with small, white, saucer-shaped flowers, such as those of Mitella pentandra, all seem to be pollinated by fungus gnats. Fungus gnats are themselves quite small and their larvae live in moist soils, feeding on fungi. As it turns out, the adults are avid pollinators of many plant species and because of this, some species, like M. pentandra, have evolved a pollinator syndrome with them.
The research team also found a strong correlation between fungus gnat flowers and habitat type. They all seemed to be tied to moist forest habitats. This is because moist forests are the only place fungus gnats can live. Plants in drier habitats rarely come into contact with fungus gnats and therefore have no selective pressures to cater to these insects.
I love it when general observations based on aesthetics lead to a deeper understanding of what is going on outside.
Photo Credit: Four Corners School of Outdoor Education (http://bit.ly/1jmNLDR)
Further Reading:
http://bit.ly/1VFiHY4
Shooting Star Goals
When the move to Illinois was finalized I set a goal for this spring. It is always good to have goals and mine was to see a large population of shooting stars. I am, of course, not talking about the ones from outer space but rather plants of the genus Dodecatheon. Various nature centers in this region boast lovely photos of hillsides covered in them. Except for my time in Wyoming where Dodecatheon conjugens often kept me preoccupied on hikes, I have only seen Dodecatheon as a spattering of individuals. This past weekend I met my goal.
We were hiking up a wooded hillside when I noticed a few rosettes of fleshy, light green leaves. This is where having a search image comes in handy. There was no mistaking these plants. At first it seemed as if we were meeting a bit too early. I could just make out some flower buds poking up from the middle of the rosette. However, further up on the ridge, a warmer microclimate rewarded us with quite the display. All along the sun-streaked hillside were hundreds of shooting stars just starting to bloom. What's more, these were a unique species of shooting star I had never seen before.
Dodecatheon frenchii is as Midwestern as it gets for this genus. This particular species is known from only six states. It prefers to grow in shallow sandy soils along the southern edge of the glacial boundary. Often times it can be found at the base of sandstone cliffs and ledges. Taxonomically speaking, this species is quite interesting. It is very similar to D. meadia. In fact, some authors lump them together. The greatest difference between these plants, however, lies in their chromosomes as well as their habitat preferences. D. frenchii is diploid and is a sandstone endemic, whereas D. meadia is tetraploid and much more widespread.
Despite their limited range, D. frenchii are quite hardy. Growing in sandy soil has its challenges. The biggest issue plants face is drought. When summer really heats up, these plants go dormant. Their thick roots store water and nutrients to fuel their growth the following year. Due to the nature of their preferred habitat, few other plants can be found growing with D. frenchii. That's not to say nothing can, however, competition is minimal. As such, D. frenchii does not compete well with other plants, which certainly sets limits on its preferred habitat. Like all members of this genus, D. frenchii flowers are adapted for buzz pollination. Certain bees, when landing on the downward pointing stamens, vibrate their bodies at a special frequency that causes pollen to be released.
Seeing these plants in person lived up to all of the hype. It was one of those botanizing moments I will never forget. Although I often go outside with the simple goal of just being in nature, sometimes having a specific mindset makes for a fun adventure. If anything, it makes for some great bonfire stories. So here's to spring and to Dodecatheon and to just getting outside.
Further Reading:
http://bit.ly/1U69kj1
http://bit.ly/1rht7Bl
Lovely Lomatium
I officially learned how to botanize in the American west. Before then my skills were limited to "hey, look at the pretty flower" and then Googling my way to an answer. As such, I have a real soft spot for western botany. Despite the fact that I have not had the chance to exercise those muscles in some time, I nonetheless revisit the few groups that I do remember via the massive photo collection I built up during my tenure in Wyoming. One group I am particularly fond of are members of the genus Lomatium.
I had never really paid attention to members of the carrot family. I always associated that group with the Queen Anne's lace (Daucus carota) I encountered growing in ditches. In other words, I found them boring. All of that changed when I moved to Wyoming. Spring was slow to start that year. I mean really slow. I thought I had it bad in western New York where spring snow storms and freezing temperatures often delayed plant growth well into May. That year in Wyoming, the last snow storm hit on June 29th. Because of this, most of the plants we were trying to locate were biding their time underground waiting for favorable weather to kick off the growing season.
By mid June I was starving for plant life. I needed to see some greenery. That is when I first laid eyes on a Lomatium. They began appearing as tight clusters of highly dissected, rubbery leaves. Once I knew what to look for, I began finding them throughout the foothill regions where we were working. Since I was just getting familiar with the local flora, I was hard pressed to key anything out. Instead I just waited for flowers. I didn't have to wait very long.
Soon entire hillsides were covered in little yellow umbels. They were squat plants, never growing too high. The constant winds that whipped across the terrain made sure of that. It soon became apparent that Lomatiums don't waste any time. Water is limited in these habitats and they have to make quick work of it while it is available. Another interesting thing to note is the sex of the flowers. Generally when I see a dense umbel like that, I just assumed they were hermaphroditic. In at least some Lomatium, this is actually not the case. The sex of the flowers is determined by age.
Smaller plants tend to produce male flowers, whereas larger plants will produce hermaphrodites. This makes a lot of sense as producing only pollen requires much fewer resources than producing ovaries and eventually seeds. Needless to say, larger plants also produce the most seed and are often the driving force in population persistence and growth. The seeds themselves are quite interesting. They are winged and often quite fleshy until they dry. Wind is the predominant seed dispersal mechanism and there is no shortage of wind in sagebrush country.
The phylogeny of this genus is quite confusing. I certainly haven't gotten my head wrapped around it. Individuals are notoriously hard to identify both physically and genetically. There is a large degree of genetic variation between plants and "new species" are still being discovered. At the same time, there is also a lot of endemism and some species like Lomatium cookii and Lomatium dissectum are of conservation concern. Aside from habitat destruction, over-grazing, and limited ranges, over-collection for herbal uses poses considerable threat to many species.
Further Reading:
Meeting Blue-Eyed Mary
For some plant species, pictures will never do them justice. I realized this when I first laid eyes on a colony of blue-eyed Mary (Collinsia verna). I was smitten. These lovely little plants lined the trail of a floodplain forest here in central Illinois. It was the blue labellum that first caught my eye. After years of reading about and seeing pictures of these plants, meeting them in person was a real treat.
C. verna is winter annual meaning its seeds germinate in the fall. The seedlings lie dormant under the leaf litter until spring warms enough for them to start growing. Growth is rapid. It doesn't take long for them to unfurl their first flowers. And wow, what flowers they have!
The bicolored blooms are a real show stopper. The lower lip contrasts starkly with the white top. It's about as close to true blue as a flower can get. Not only are they beautiful, the flowers are marvels of evolution, exquisitely primed for pollination by large, spring-hardy insects. When something the size of a bumble bee lands on the flower, the lower lip parts down the middle, thrusting the reproductive bits up against the abdomen. This plant doesn't take any chances.
Being an annual, C. verna can only persist via its seed bank. Populations can be eruptive, often appearing in mass after a disturbance clears the forest of competition. Most populations exist from year to year as much smaller patches that slowly build the seed bank in preparation for more favorable conditions in the future. Because of its annual life cycle, C. verna can be rather sensitive to habitat destruction.
Seeing this plant with my own eyes far exceeded my expectations. It was one of those moments that I couldn't peel myself away from. I love spring ephemerals and this species has skyrocketed to the top of my list. Its beauty is made all the more wonderful by its ephemeral nature. Enjoy them while they last as it may be some time before you see them again.
Further Reading: [1] [2] [3]
What is the Most Common Flower Color?
Photo by Mor licensed under CC BY-NC 2.0
Have you ever wondered what the most common flower color is? If one were to tally up all the known flowering plants, what color or colors would come out on top? I have pondered this time and again and I for some reason have a bias towards yellow. I think it is a symptom of where I live. In fact, I think flower color in general can, in part, be considered a function of geographic location. Each region of the world has its own specific pollinators driving selection for flower color. I decided to finally try and track down an answer to this question.
The truth of the matter is, no one really knows. There is simply no database out there that fully characterizes all the colors flowers can be, let alone rank them by abundance. When you really think about it in the context of real world examples, it makes sense that this would be a daunting task. The first question becomes "how do we define the color of a flower?" This may seem silly but think about it. How many times has a field guide said one thing and reality says another? This is the main reason I don't use Peterson's Field Guide to Wildflowers. Colors vary from genus to genus and heck, they even vary within a species. A plant growing in one area may look one way while the same species growing in another area can look totally different. Far from being simply a function of genes, flower color can be just as dependent on growing conditions.
Also, what one botanist calls red may not be what everyone else calls red. Barring a persons ability to see all of the visible light spectrum, there is no set standard, for flowers at least, as to where we draw the lines between colors. What we end up with at the end of the day are lumped packages of color pertaining to a chunk of the spectrum visible to us. It is actually an easier question to ask "what is the rarest flower color?" To that, most botanists will probably say black. To the best of my knowledge, there is only one species of plant in the world with truly black flowers. The rest are more accurately deep shades of red or purple. True blue is another rare color among flowers for the same reason.
After a few hours (more than I should have dedicated to the cause) I came up with one satisfying answer and to sum it all up, I will put it this way: We simply have no idea what the most common flower color is in the world but it's probably green. We tend to only pay attention to the showiest flowers. Big or small, we like bright colors and we like weird colors. All the rest just get glazed over. In reality, many plant species, especially trees, produce small, non-descript green flowers. For this reason I would say that green is a safe default until someone or a group of someones puts in the time that would be needed to put any meaningful numbers to this inquiry.
Photo Credit: Mor (http://bit.ly/1y0WnJd)
Throwing it to the Wind
Though many of you may be cursing this fact, in the temperate regions of the north, wind pollinated trees are bursting into bloom. Their flowers aren't very showy. They don't have to be. Instead of relying on other organisms for pollination, these trees throw it to the wind, literally.
It is an interesting observation to note that the instances of wind pollinated tree species increases with latitude and elevation. This makes a lot of sense. It is most effective in open areas where wind is at its strongest. That is why many wind-pollinated trees get down to business before they leaf out.
The fewer obstructions the better. Also, pollinators can be hard to come by both at high elevation and high latitudes. Therefore, why not let the wind do all the work? This is also why wind-pollination is most common in early succession and large canopy species. Similarly, this is also why you rarely encounter wind-pollinated trees in the tropics. Leaves are out year round and pollinators are in abundance.
Without pollinators, wind-pollinated trees don't need to invest in showy flowers. That is why they often go unnoticed by folks. Instead, they pour their energy into pollen production. Your irritated sinuses are a vivid reminder of that fact. Wind pollination is risky. It relies mostly on chance. Therefore, the more pollen a tree pumps out, the more likely it will bump into a female. However, some trees like red maples (Acer rubrum) combine tactics, relying on both wind and hardy spring pollinators for their reproduction.
Whether you love this time of year or dread it, it is nonetheless interesting to see how static organisms like trees cope with the difficulties of sexual reproduction. I enjoy sitting in my yard and watching pines billow pollen like smoke from a fire. If anything, it is a stark reminder of how important sexual reproduction is to the myriad organisms on this planet.
Further Reading:
http://bit.ly/1qnRUm2
Paleo Pinus
Photo Credit: Howard Falcon-Lang, Royal Holloway University of London
What you are looking at here is the oldest fossil evidence of the genus Pinus. Now, conifers have been around a long time. I mean really long. Recognizable members of this group first came onto the scene sometime during the late Triassic, some 235 million years ago. Today, one of the most species-rich genera of conifers are those in the genus Pinus. They dominate northern hemisphere forests and can be found growing in dry soils throughout the globe. For such a commonly encountered group, their origins have remained a bit of a mystery.
The fossil was discovered in Nova Scotia, Canada. Unlike the rocky fossils we normally think of, this fossil was preserved as charcoal, undoubtedly thanks to a forest fire. The degree of preservation in this charcoal specimen is astounding and provides ample opportunity for close investigation.
I mentioned that this fossil is old. Indeed it is. It dates back roughly 133 –140 million years, which places it in the lower Cretaceous. What is remarkable is that it predates the previous record holder by something like 11 million years. Even more remarkable, however, is what this tiny fossil can tell us about the ecology of Pinus at that time.
Firstly, the leaf scars indicate that this tree had two needles per fascicle. This implies that the genus Pinus had already undergone quite the adaptive radiation by this time. If this is the case, it pushes back the clock on pine evolution even earlier. Another interesting feature are the presence of resin ducts. In extant species, these ducts secrete highly flammable terpenes, which would have potentially promoted fire.
Species that exhibit this morphology today often utilize an ecology that promotes devastating crown fires that clear the land of competition for their seedlings. Although more evidence is needed to confirm this, it nonetheless suggests that such fire adaptations in pines were already shaping the landscape of the Cretaceous period. All in all, this fossil is a reminder that big things often come in small packages.
Photo Credit: Howard Falcon-Lang, Royal Holloway University of London
Further Reading:
Sand Armor
Photo by Franco Folini licensed under CC BY-SA 2.0
Plants go through a lot to protect themselves from the hungry jaws of herbivores. They have evolved a multitude of ways in which to do this - toxins, stinging hairs, thorns, and even camouflage. And now, thanks to research by a team from UC Davis, we can add sand to this list.
At this point you may be asking "sand?!" Stick with me here. Undoubtedly you have noticed that sticky plants often have bits of whatever substrate they are growing in stuck to their stems and leaves. You wouldn't be the first to notice this. Back in 1996 a term was coined for this very phenomenon. It has been called “psammophory,” which translates to "sand-carrying."
Over 200 species of plants hailing from 88 genera in 34 families have been identified as psammorphorous. The nature of this habit has been an object of inquiry for at least a handful of researchers over the last few decades. Hypotheses have ranged from protection from physical abrasion, reduction of water loss, reduced surface temperature, reduced solar radiation, and protection from herbivory.
It was this last hypothesis that seemed to stick. Indeed, many plants produce crystalline structures in their tissues (phytoliths, raphides, etc., which are often silica or calcium based) to deter herbivores. Sand, being silica based, is known to cause tooth wear in humans, ungulates, and rodents. Perhaps a coating of sand is enough to drive away insects and other hungry critters looking to snack on a plant.
By controlling the amount and color of the sand stuck to plants, the researchers were able to demonstrate that plants covered in sand were less palatable to both mammalian and insect herbivores. In total, sand-covered individuals received significantly less damage to their leaves than individuals that had their sand coat removed. By altering the color of the sand, the researchers were able to demonstrate that this was not a function of camouflage. In total, the presence of sand led to an overall increase in fitness due to a decrease in damage over time. These results are the first conclusive evidence in support of psammophory as yet another fantastic plant defense mechanism.
Photo Credit: Franco Folini (bit.ly/1RApG1R) and Wolfram Burner (http://bit.ly/1RMNR9V)
Further Reading:
http://onlinelibrary.wiley.com/wol1/doi/10.1890/15-1696/abstract
Photo by Wolfram Burner licensed under CC BY-NC 2.0
The Fall of Corncockle
Photo by Sonnentau licensed under CC BY-NC 2.0
This switch from more traditional farming practices to industrialized monocultures has left a damaging legacy on ecosystems around the globe. This is especially true for unwanted plants. Species that once grew in profusion are now sprayed and tilled out of existence. Nowhere has this been better illustrated than for a lovely little plant known commonly as the corncockle (Agrostemma githago).
This species was once a common weed in European wheat fields. Throughout much of the 19th and early 20th century, it was likely that most wheat sold contained a measurable level of corncockle seed. Its pink flowers would have juxtaposed heavily against the amber hue of grain. Indeed, its habit of associating with wheat has lead to its introduction around the globe. It can now be found growing throughout parts of North America, Australia, and New Zealand.
However, in its home range of Europe, the corncockle isn't doing so well. The industrialization of farming dealt a huge blow to corncockle ecology. The broad-scale application of herbicides wreaked havoc on corncockle populations. Much more detrimental was the switch to winter wheat, which caused a decoupling between harvest time and seed set for the corncockle. Whereas it once synced quite nicely with regular wheat harvest, winter wheat is harvested before corncockle can set seed. As such, corncockle has become extremely rare throughout its native range and was even thought to be extinct in the UK.
A discovery in 2014 changed all of that. National Trust assistant ranger Dougie Holden found a single plant flowering near a lighthouse. Extensive use of field guides and keys confirmed that this plant was indeed a corncockle, the first seen blooming in the UK in many decades. It is likely that the sole plant grew from seed churned up by vehicle traffic the season before.
Photo Credit: sonnentau (bit.ly/1qo3XQK)
Further Reading:
Clapham, A.R., Tutin, T.G. and Warburg, E.F. 1968. Excursion Flora of the British Isles. Cambridge University Press
The Dune Building Powers of Sand Cherry
Throughout a surprising amount of North America, dunes and other highly erosional habitats have a friend in the sand cherry (Prunus pumila). I first met this cherry on the shores of Lake Huron where it blankets dunes with its scrambling, prostrate branches.
Sand cherry can be found growing in dry, sandy areas. Its ability to grow in such places makes it an important soil stabilizer and dune builder. It sends down a deep root system that anchors sand in place. As the dune system grows, it sends out more and more branches, further stabilizing these relatively unstable habitats. This also begins the process of soil formation. By stabilizing the sandy dune soils, sand cherry enables other plants to take root. This in turn leads to the colonization of microbes and invertebrates that begin breaking down biological materials, thus forming the foundation of organic soil.
Photo by Joshua Mayer licensed under CC BY-SA 2.0
Mature sand cherries begin blooming in April and will continue doing so into June in cooler climates. The flowers are followed by small cherries that are relished by a variety of animals. Aside from food, its thick growth habit also provides ample shelter and breeding opportunities for a insects, birds, and mammals alike.
Taken together, sand cherry is quite the ecosystem engineer. Because of its drought tolerance, sand cherry is also gaining some popularity among habitat restoration practitioners as well as anyone looking for hardy yet beautiful landscape specimen. Individuals growing on more stable, less wind-swept ground will take on a more upright appearance. All in all this may be one of my favorite members of the genus Prunus.
Photo Credit: Joshua Mayer (http://tinyurl.com/znrh8e2)
Further Reading: [1]
Why You Should Never Buy Cypress Mulch
Photo by Jesse Reeder licensed under CC BY-NC-ND 2.0
Gardening season is soon to be underway here in the northern hemisphere. This past weekend saw droves of people taking advantage of the nice weather by getting their hands dirty in the garden. A walk around the neighborhood brought with it a lot of smiles and a chance to reconnect with neighbors I haven't talked to in a while but it also brought with it something sinister. Lingering in the air was the scent of cypress mulch. Tons upon tons of it are being spread over gardens everywhere. One might ask "Whats the problem? Cypress mulch is more durable and more insect resistant than other mulches!"
WRONG!
Anymore today, these ideas are leftovers of a long gone era. Back when old growth cypress forests were still a thing, these centuries old trees did impart rot and pest resistance into their wood. Today, this is not the case. Because logging has taken most of the old growth cypress from places like Florida and Louisiana, mulch companies have had to resort to cutting down and mulching young, second and third growth cypress stands. Barely given the time to grow into the towering specimens their parents and grandparents once were, these young trees have not yet imparted the centuries worth of compounds into their wood that keep them from rotting and deter insect predators.
The saddest part of the cypress mulch industry is that they are destroying valuable and irreplaceable habitat for the myriad lifeforms that rely on cypress swamps for their existence. To add insult to injury, recovery of cypress trees is almost negligible anymore today due to the way we have managed our waterways. Cypress seedlings require inundation by freshwater and regular silt deposition in order to successfully germinate. A century of flood control, inundation by brackish water, as well as dam and ship canal building have completely upset this dynamic. Now, instead of building new habitat for cypress swamps, these sediments are washed away, far out into the Gulf of Mexico.
What staggeringly few people seem to care to realize is that cypress swamps are our first line of defense against hurricanes. Cypress swamps can cut the force of a storm surge by 90%. It has been estimated that the cypress swamps in Louisiana alone are worth a staggering $6.7 billion in storm protection every year. That is a lot of cash, people!
As with any other industry, the cypress mulch companies are driven by consumer demand. The simple act of individuals, communities, and local governments not purchasing this nasty product is all it will take to lessen the blow to these precious habitats. At the rate cypress is being cut, it will not take long for us to exhaust the resource entirely. As you are looking to do some gardening this year, and many years into the future, please keep these great trees in mind and stop buying cypress mulch. In lieu of wood and bark mulches, you should consider using shredded leaves from your property instead. They make excellent mulch and being locally sourced, the reduce the chances of introducing disease and other pests to your landscape. In the words of Captain Planet, "the power is yours!"
Photo Credit: Jesse Reeder (http://bit.ly/1wmQpn8)
Further Reading: [1] [2] [3] [4]