The Tallest of Palms

High up in a mountain valley in Colombia grows one of the most remarkable palms in the world. Known scientifically as Ceroxylon quindiuense, the Quindío wax palm towers like a lanky monolith above the surrounding vegetation. Not only is this the tallest species of palm in the world, it is, by extension, the tallest monocot as well.

Standing at heights of over 160 feet, the Quindío wax palm looks all the stranger with its narrow trunk and tuft of fronds all the way at the top. It is called a wax palm because members of this genus produce a waxy substance from their trunk. In the past, this wax was harvested for its use in making torches. Until electricity became widely available, these palms were felled en masse for this purpose.

Quindío wax palms are slow to mature. For at least 15 years they focus much of their energy on radial or outward growth of the trunk. For 15 years, all the tree puts out are three pinnate leaves. Things change once the tree hits 15. It will begin its climb into the sky. Every year it sheds leaves, which creates a dark ring around the trunk. Because of this, it is easy to estimate the approximate age of any given wax palm. Count the rings and add 15 years for stem development plus another 5 for a full crown. It is believed that these palms can take upwards of 80 years to reach sexual maturity!

Because of its limited geographic range, Quindío wax palms are at risk of extinction. The young fronds are favorites among Catholics of the region for their use in Palm Sunday ceremonies. Stands that exhibit heavy harvesting have a hard time of recovering. At the same time, their native range is quickly being converted to pasture land as well as other forms of agriculture. Even if trees are left standing, their seeds find it difficult to germinate and survive under the altered microclimates of these human environments.

Luckily for Ceroxylon quindiuense, the government of Colombia recognizes how special this species is. Not only is it now the national tree and emblem of Colombia, its is now a protected species. All logging of Quindío wax palms is illegal. Still, major portions of their remaining populations are located within pasture lands.

Photo Credit: nuria mpascual (http://bit.ly/1CImC7T)

Further Reading:
http://bit.ly/1CImCEP

http://www.iucnredlist.org/details/38467/0

Unlikely Allies

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

On the Balearic Islands of Spain, an interesting relationship has developed between a plant and an animal. What's more, this relationship seems to have developed relatively recently in the history of these two species. The players in this story are the dead horse arum (Helicodiceros muscivorus) and an unsuspecting lizard known as Lilford’s wall lizard (Podarcis lilfordi).

Podarcis lilfordi is a lot like other fence lizards. They spend their days basking in the sun’s warmth and hunting for insect prey. They also have a tendency to feed on nectar and pollen, making them important pollinators of a handful of plant species around the island. For the dead horse arum, however, its not about pollination.

Like most members of its family, the dead horse arum relies on trickery for sex. As its common name suggests, the dead horse arum both looks and smells like rotting meat. Unsuspecting flies looking for a meal and a place to lay their eggs find the dead horse arum quite attractive in this regard. The plant even steps up its game a bit by producing its own heat. This helps volatilize its smell as well as to make it a cozy place worth investigating. Studies have found that during the peak flowering period, the inflorescence can be upwards of 24 °C (50 °F) warmer than its surroundings.

Photo by Marina Sanz Biendicho licensed under CC BY 2.0

As one would expect, this has caught the attention of the cold blooded lizards. Enticed by the heat source, lizards basking on the spathe quickly realize that the plant is also a great place to hunt. Flies attracted to and trapped by the flowers make an easy meal. On the surface this would seem counterproductive for the dead horse arum. What good is an animal hanging around that eats its pollinators?

The relationship doesn't end here though. At some point in recent history, a handful of lizards figured out that the seeds of the dead horse arum also make a great meal. This behavior quickly spread through the population to the point that Podarcis lilfordi regularly break open the seed heads and consume the fleshy berries within. Here's the catch, seeds that have passed through a lizards gut are twice as likely to germinate.

Researchers have been studying this interaction since 1999. Since then, the dead horse arum has gone from being relatively rare on the island (~5,000 individuals per hectare) to a density of roughly 30,000 individuals per hectare during the 6 year span of the study! Even though the lizards eat their pollinators, the dead horse arums of Aire Island have nonetheless benefited from interactions with their cold blooded companions.

Sadly, this novel relationship may not last too long. The introduction of cats and rats to the islands has drastically reduced the population of these lizards to the point that the IUCN has listed them as an endangered species. Research will be needed to see if the dead horse arum follows in their wake.

Photo Credit: [1] [2]

Further Reading: [1] [2]

A Mallow Called Kankakee

In the spirit of this week's podcast I would like to take a look at a very special plant. It happens to be one of the rarest plant species in the lower 48. What may surprise you even more is that this species is endemic to a small island in the middle of the Kankakee River of Illinois called Langham Island. I am, of course, talking about the Kankakee mallow (Iliamna remota).

It is strange to think of something endemic to a 20 acre island in the midwest but that seems to be the case. Though disjunct populations have been located in Indiana, experts feel that these were the result of early attempts at saving this species from extinction. In fact, the rarity of this plant was realized quite early on. A series of taxonomic revisions made it so that by the early 1920's, botanists knew that Iliamna remota was distinct from similar species such as liamna rivularis and Iliamna corei.

Despite its uniqueness, there doesn't seem to be too many explanations as to why this species is limited to Langham Island. Perhaps our recent glacial past has something to do with it. It very well could also be due to the fact that roughly 80% of Illinois has been converted to farmland. It is also due, in part, to the lack of life-giving fires that the prairies so desperately need. Indeed, after decades of attention, Langham Island and the Kankakee mallow seemed to have faded from the spotlight.

In 1981, botanists realized that most of the plants on the island had disappeared. Only 109 individuals remained and no seedlings were found. It was starting to look like this species was doomed to extinction. Growing up in their place were thick stands of Japanese honeysuckle and multiflora rose. Luckily a handful of concerned biologists decided to light some fires. Wherever the fires burned away the invasive competition, seedlings began to emerge. Close inspection would reveal that these were the next generation of Kanakakee mallow!

A missing piece of this biological puzzle had been restored. The mallow seeds were waiting in the soil for a fire to release them from the tyranny of these invaders. It would seem that the future of this species was a bright one. Sadly, another round of budget cuts coupled with a decrease in public interest had swept through the region. When a group of botanists again went looking for this species in the summer of 2014, they realized that, to their horror, history seemed to have repeated itself. Gone were the remaining populations of the Kankakee mallow. Honeysuckle and multiflora rose had returned with vengeance.

It was clear that if this species were to be saved, Langham Island would need more dedicated attention. Thus the Friends of Langham Island was born. Since then, brush cutting and controlled burns have meant that the Kankakee mallow has once again rose from the ashes, literally. Ongoing attention from a concerned group of citizens may be the only means left at saving this endangered plant.

Photo Credit: Prairie Moon Nursery

Further Reading:
www.habitat2030.org

Check out The Brain Scoop's video about this plant

Listen to a podcast episode dedicated to the restoration of these species' habitat

The Largest Seed in the World

Photo by Reed Wiedower licensed under CC BY-SA 2.0

For Lodoicea maldivica, better known as coco de mer, producing the largest seeds in the world may seem like a cool fact for the record books but it certainly has its drawbacks. However, as with anything in nature, selection would not allow for wasteful traits to be passed on. Costs must be offset by a reproductive advantage on some level. A recent study looked at what these tradeoffs might be for L. maldivica and what they found is pretty incredible.

With seeds clocking in at upwards of 30 kg (66 lbs.) one has to wonder what L. maldivica is up to. It was long thought that, like the coconut, seeds of this palm must be dispersed by water. However, they are simply too dense to float. Instead, seed dispersal for this peculiar species of palm is actually quite limited. They simply fall from the tree and germinate below the canopy.

Photo by Wendy Cutler licensed under CC BY 2.0

This may explain why L. maldivica is endemic only to the islands of Praslin and Curieuse in the Seychelles. It's not just the seeds that are huge either. The female flowers, which are borne on separate trees than the males, are the largest female flowers of any species of palm. At 10 m (32 ft.) in diameter, the leaves are also massive, fanning outwards on petioles that can reach 2 m to 4 m (6.5 - 13 ft) in length. It goes without saying that L. maldivica is a palm full of superlatives.

Counterintuitively, the habitats in which they grow are notoriously low in nutrients. Why then would this palm invest so much energy into growing these gigantic structures? Because they tend to germinate and grow beneath their parents, the offspring of L. maldivica would appear to be at a disadvantage from the start. A recent study suggests that the answer lies in those massive leaves.

Researchers found that the areas directly beneath the adult trees were wetter and had more soil nutrients compared to the surroundings. As it turns out, L. maldivica modifies its own habitat. Those massive leaves do more than just collect sun, they also act as giant funnels. In fact, most of the water that rains down onto the canopy is collected by the leaves. In this way, everything from water, debris, and even excess pollen is funneled down to the base of each tree.

Photo by Ji-Elle licensed under CC BY-SA 3.0

Not only is this good for the parent tree, it is also a boon for the dispersal-limited offspring. Coupled with the considerable endosperm in those massive seeds, all of this additional water and fertilizer means that seedling L. maldivica enter into the world at a distinct advantage over many other plants on the islands. All of that endosperm serves to help fuel seedling growth while it is still shaded by its parent.

Sadly, over-harvesting of the seeds has crippled natural reproduction for L. maldivica. This coupled with habitat destruction paints a bleak picture for this record-holding palm. It has already been lost from three other Seychelles islands. Luckily there are many conservation efforts underway that are aimed at saving L. maldivica. The Seychelles are now considered a World Heritage Site and many of the wild populations of this palm lie within national parks.

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

Further Reading: [1] [2]

Common Yet Endangered Palms

Raise you hand if you have ever had a parlor palm (Chamaedorea elegans). I see most of you have raised your hands. Palms in the genus Chamaedorea are the most commonly kept palms on the market. They are small, very shade tolerant, and nearly indestructible. The clear winner in this regard is the parlor palm. We have all given these little palms a shot at one time or another. They are so common that we rarely give a second thought as to where they come from. Surely they did not evolve in a nursery. It may surprise you that for as ubiquitous as these palms are, they are actually quite threatened in the wild.

The genus Chamaedorea is endemic to sub-tropical forests of the Americas and is comprised of roughly 80 species. They are understory palms that are most at home under the deep shade of the canopy. Most species are generally pretty small, rarely growing over 10 feet. All of these factors add up to some resilient and fun houseplants. It doesn't take much to keep them happy. Every once in a while they will produce flowers. Though small, they are often brightly colored. The preferred method for mass cultivation is via seed. However, seed production outside of their native range is notoriously difficult and often requires human intervention. For this reason, a vast majority of nursery grown palms are grown from wild collected seeds.

This may not seem like a bad deal until you look at the numbers. I have seen reports of over 500 million seeds exported from Mexico annually. Couple this with the fact that many species of Chamaedorea are known to grow in very restricted ranges and suddenly the picture becomes very bleak. Over collecting of seeds has decimated wild populations. Without seeds there is no recruitment, no seedlings to take the place of adult plants.

Another considerable threat to these palms comes from the cut flower industry. Palm fronds are notoriously gorgeous and many people like to include them in their displays. Most of the leaves cut come from wild plants. Normally palm fronds are harvested in a manner that doesn't kill the plant, however, in Mexico children are often employed to collect them and their lack of experience can severely damage wild populations.

On top of all of this, the forests in which these palms grow are now being converted to agriculture. If actions are not taken to limit the abuse of wild populations, it is likely that some of the most commonly encountered house plants are going to be extinct in the wild. This is a hard pill to swallow. If you have any of these species growing in your home, take care of them. Perhaps knowing how uncertain the future is for many of these palms will earn them a little more respect.

Here is a list of some of the most threatened species in this genus:

Chamaedorea amabilis
Chamaedorea klotzschiana
Chamaedorea metalica
Chamaedorea pumila
Chamaedorea sullivaniorum
Chamaedorea tuerckheimii

Photo Credits: Michael Wolf (http://bit.ly/16suMsf), scott.zona (http://bit.ly/1zHdUII),

Further Reading:
http://bit.ly/1ADC3mw

An Endangered Orchid from China

Cypripedium fargesii is a critically endangered orchid native to the mountains of Sichuan, Gansu, and Hubei China. It is believed that this orchid mimics certain types of fungi in order to attract and dupe flies into pollination. Threats to this species include habitat destruction and poaching. It is believed that only 250 mature individuals exist in the wild. 

Photo Credit: Steve Garvie (http://bit.ly/1LmNgv8)

Further Reading:
http://www.pnas.org/content/108/18/7478.short

http://www.iucnredlist.org/details/46647/0