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…

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]

A Flower Trapped in Amber

Photo by George Poinar [SOURCE]

Photo by George Poinar [SOURCE]

Thanks to a 30 year old collection of amber tucked away in the drawers of a museum, we now have the first fossil record of the asterid lineage. Discovered in the Dominican Republic back in 1986, this particular chunk of amber contains a tiny flower about a centimeter in length. The preservation is astounding, allowing researchers to accurately identify this as a member of the genus Strychnos.

The asterid lineage contains many orders that we would be familiar with including Gentianales, Lamiales and Solanales. It is highly derived yet poorly represented in the fossil record. Because of the challenges associated with accurately dating amber, scientists estimate that this flower is somewhere between 15 - 45 million years old. To put this in perspective, North and South America were not even connected at this point in time. What's more, the details preserved in these amber deposits are allowing researchers to piece together what the forest in this region would have looked like.

These fossils show that this forest "contained a distinct canopy layer composed of legumes such as algarroba (Hymenaea protera), cativo (Prioria spp.) and nazareno (Peltogyne spp.), with emergent trees like caoba (Swietenia; Meliaceae) extending through the canopy. The subcanopy and understory were represented by royal palms (Roystonea) and figs (Ficus; Moraceae). The shrub layer included other types of palms as well as acacias. Grasses like pega-lega (Pharus) and bambusoids (Alarista) colonized the forest floor. Orchids, bromeliads, ferns and vines covered the trees, and various lianas were also part of this tropical forest."

Pretty amazing for bits and pieces of solidified tree sap. This particular flower has been named Strychnos electri, a now extinct species. However, the morphological characteristics show that this particular genus as well as the asterid lineage were already well established at this time. Discoveries such as this are offering highly detailed windows into the past, which allows us to better understand flowering plant evolution and ecosystem change.

Photo Credit: George Poinar

Further Reading:
http://www.nature.com/articles/nplants20165