The lemur-faced traveller's palm

Species name: Ravenala madagascariensis

Common name: traveller's palm, traveller's tree

Location: Dominican Republic (the last two photos are from Wikipedia)

The traveller's palm is native to, as you should be able to deduce by the name, Madagascar. It is still planted there as an ornamental species, and is also planted in tropical and subtropical locations worldwide for the same purpose. That being said, this species is rarely found growing in wild, undisturbed areas in Madagascar (which now are very few and far between) and so is at risk of extinction in the wild. This seems to be the case for almost every species native to Madagascar; the expanding cities due to a growing population as well as suitable lands for agriculture are putting all of their native flora and fauna at risk. It's not as short a trip as it seems to get to mainland Africa!

The traveller's palm, often confused for a member of the banana genus (Musa) because of their very similar leaf morphologies, is actually more closely related to ginger than it is to banana. It is the only species in the genus, and there are two other genera that are closely related: the African Birds of Paradise (Strelitzia), and the South American fan palm (Phenakospermum; not even remotely related to the true fan palm which I will profile in a later blog). The South American species, while very popular in Brazil, is rarely used as an ornamental species because of how easily it is destroyed in hurricanes and rain storms with high winds (the stem, while appearing very strong, can actually be cut with a single blow by a machete!).

Why the traveller's palm, you ask? Well, there are two stories for how this common name arose. First, we'll start with the biological reason: the plants almost exclusively grow in an east-west direction. Why is this the case? I don't think anyone has actually looked into why but it probably has something to do with maximizing absorption of light by the leaves. Regardless of why this occurs, it can be used as a crude compass if lost. The other reason it has this common name is because of the fact that the petioles of the leaves catch rainwater where it is stored at the base of the leaves. Rumour has it that you can drink it if you are in desperate need. But you know what else is stored at the base of the petioles? Bugs, scorpions, mud, fungal spores, and bacteria. There is NEVER a time when you should drink the water found at the base of the leaves of a traveller's palm! Even after being purified, it will still have a pretty raunchy smell.

This plant is a very cool example of coevolution between a plant and an animal. The only known pollinators of the flowers of this plant (flowers I didn't actually get a chance to photograph during my trip but Wikipedia has some lovely photos of them) is the ruffled lemur, a primate also native to, and only found on the island of, Madagascar. The long noses of the ruffled lemur almost perfectly coincide with the very long bracts of the inflorescences of the flowers, and the nectaries are actually found under the flowers in the bracts. The lemur climbs up the plant in search of a quick source of sugar, only to have their face covered in pollen of the flower. The next flower they visit has all of the pollen deposited on it, and fertilization occurs. Since they are the only animal that can pollinate the flowers, you will never see the fruit or the seeds being produced anywhere other than in Madagascar, which is a shame; they are a brilliant colour of blue!

The ruffled lemur, the pollinator of the traveller's palm. Isn't it cute?! (Photo source: Wikipedia)

What's the name of this plant again?

Species name: Ginkgo biloba

Common name: ginkgo, maidenhair tree

Location: Ontario

Up until relatively recently (late 1700s to early 1800s), this species of tree was well known from the fossil record (along with the approximately 8 other species in the genus) but believed to be extinct in the wild. There were a few living specimens known at the time in China, Korea and Japan that had been cultivated and tended by monks for thousands of years, and so they were considered to be, quite literally, living fossils. Two stands of trees were discovered in China and from those two remaining small populations, all of the rest of the trees in cultivation around the world were derived. Unfortunately, it was discovered recently that the two remaining natural populations show an incredibly high level of genetic uniformity (suggesting they might, in fact, be two "families" of trees and therefore very closely related to each other) which puts them at great risk should a pathogen develop that targets ginkgo trees. This probably isn't an "if" and more a "when"! Like bananas, all of the ginkgo trees would be wiped out if we couldn't come up with a solution in time. Similarly to the Dawn redwood, the ginkgo tree is monotypic, meaning that it is the only remaining species in the genus, and all of the rest of the close relatives to this species are known only from fossils. You can read all about the Dawn redwood HERE. Interestingly enough, the Dawn redwood, like the ginkgo, is also critically endangered in the wild.

There are two characteristics about the ginkgo that are worth noting. The first is that these trees are dioecious, meaning that there are separate male and female trees. If you're planting a ginkgo tree on your property for purely ornamental purposes, make sure you choose a male tree! The female trees are the ones that bear the fruits, and the fruits have a hideous smell (think of the smell of rotting, rancid butter and that will begin to describe it...) that lingers throughout the winter with every temporary melt of snow. If you would like to plant the tree to consume the seeds for their reported medicinal values, make sure you plant both a male and a female tree to ensure large amounts of seed production. The second interesting characteristic about this tree is that they don't actually produce fruit, because fruit can only be produced by Angiosperm trees and this is a Gymnosperm. This means that the ginkgo, despite looking like it has broad leaves (similar to something like a maple or aspen or oak) it actually has modified needles (like pine or spruce or a cycad)! The "fruits" are actually just seeds with a swollen outer surface called a sarcotesta, and is developmentally very different than the fleshy part of a fruit. Once that layer is removed (should you attempt this insane, smelly feat, WEAR GLOVES! The smell, once on your skin, has to be leeched out, not washed out!), the remaining seed "shell", the sclerotesta is revealed and it looks a whole lot like an unopened pistachio (but a lot bigger).

The ginkgo seeds are culinary delicacies in many locations around the world, not the least of which being in China where it is used in large amounts around Chinese New Year in a dish called Buddha's Delight (if you've never tried it, you must! It's delicious). The Japanese and Koreans also make dishes that feature the ginkgo seed, and they are served year-round (but more so on special occasions since they are expensive). The other main use of this plant aside from its culinary and ornamental uses is the medicinal use. This is actually one of the suggested reasons for the decline of the population of ginkgo trees throughout its native range. Other theories state that massive ecological changes caused drastic declines in population and the ongoing medicinal value of the plant was the straw that broke the camel's back, so to speak. Regardless, there are now plantations in China for the dedicated medicinal use of this plant.

Medicinally, the main claims to fame with ginkgo and human health revolve around memory and dementia. First, it is claimed that ginkgo supplements help with memory retention in the aging process. It is suggested that if you consume 240 mg of ginkgo extract per day it will improve your long-term memory and help prevent the onset of Alzheimer's disease. In a very large study in 2008 done by the Journal of the American Medical Association, there was no effect of ginkgo extract consumption and memory, or a correlation between ginkgo consumption in any form and the onset of Alzheimer's. People who consumed ginkgo were just as likely to get it as those that didn't. A much smaller study in 2010 by the American Geriatric Society published in the Journal of Geriatric Psychiatry showed that it had a significant effect over a placebo in people already suffering from Alzheimer's (or other diseases that are Alzheimer's-like) on memory retention. A third study showed that for up to 2.5 hours after consumption, ginkgo extract and ginkgo seeds had a significant effect on memory retention in memory-recall experiments in healthy people. So far there are no studies that show that ginkgo is harmful to your health, so if you choose to take it to improve your memory at the very least it will do nothing. But until more large-scale scientific studies start agreeing with each other, take all reported effects with a grain of salt.

Ginkgo extract does act as an anti-coagulant, so as with all medications (herbal or not), make sure you consult a doctor before taking them to make sure it won't interfere with anything you're already taking. This especially applies to those at high-risk of stroke who are already on blood-thinners like warfarin (yes, the rat poison warfarin is now a medication for humans!) or coumadin, since even a minor injury could lead to massive blood loss.

Dawn Redwood: Critically Endangered?

Species name: Metasequoia glyptostroboides

Common name: Dawn redwood

Location: Ontario

This species of redwood is unique in many ways, only one of which being that it was only recently (well, in the grand scheme of things it's recent) rediscovered in 1949 after thoughts it had gone extinct in the late 1800s. It is native to a very small region in China, and within its native range there are only a few individuals of this species left so it is critically endangered. That being said, it's also an incredibly popular ornamental tree (gaining popularity in North America) so cultivated species of this plant will likely always exist even after the wild members of the population are long gone. Another unique aspect of this tree is that unlike it's close relatives, the Giant Redwood (Sequoiadendron) and the Coastal Redwood (Sequoia), this is a deciduous tree and a conifer at the same time. It produces cones like you would picture from a redwood or even a cedar, but loses its leaves during the fall like an oak or maple tree would. As you can see from the pictures, the leaves are like feathers, and it seems like they all appear overnight after the buds have persisted on the branches for many days or weeks. While you might imagine the debris from this tree would be quite impressive since it can be a huge tree (up to 200 feet in the wild) with many leaves, the leaf-like needles actually decay very quickly. It's certainly not the padded ground cover that you find in pine plantations!

The Dawn redwood is what we refer to as being a "monotypic" species, meaning that it is the only species that is currently alive in the genus. There are an estimated three other species that have once existed in the genus based on evidence from the fossil record. These trees seemed to be abundant in the early Paleocene, between 55-60 million years ago. The changing climate likely led to their demise, which seems to be repeating itself with the last remaining species. The Dawn redwood is also very sensitive to urban pollutants, so living in the city and trying to grow one of these outside is probably a losing proposition (and a good reason why urban encroachment is one of the contributing factors to the status of the last remaining wild population of this species). That being said, this is a popular plant species to turn into a bonsai, so growing it indoors can work well if you have time and patience!

These trees are a source of national pride in China, so much so that it's actually illegal to take branch cuttings from any one of the remaining 5,000 trees left in the wild. Unfortunately, cone collection is not protected in the same way so natural regeneration of these trees has essentially stopped. Once the mature trees in the stand die, the species will be extinct in the wild. The state of North Carolina has attempted to do its part by planting an enormous stand of Dawn redwood trees over three different sites. Their goal is to have 5,000 trees planted in various stages of growth by the year 2035, which is when the nature preserve is slated to open to the public. Hopefully this enormous undertaking will continue to thrive with changing national budget priorities! I would love to go see it someday.