Sunday, March 10, 2013

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)