Friday, July 6, 2012

An epiphytic fern




Species name: Platycerium superbum

Common name: staghorn fern

Location: Dominican Republic

This species of fern is a very popular garden plant for tropical gardens, and indoor gardeners with green thumbs are also causing this plant to rise in popularity in greenhouses. This species of staghorn fern is native to a small area in Australia, but is now propagated and easily grown (without being invasive) worldwide in tropical areas. There are about 15 other species in the genus ranging in origins from South America to Asia and everywhere in between. North America and Europe are the only two continents (assuming Antarctica is a given to be inhospitable to tropical plants) that could potentially have staghorn fern habitat that have no native species.

Anyone who's been to Puerto Plata ("Silver Port" in Spanish; named after the trees that are so common there that have bright green leaves on the top but when they flutter in the wind they flip over to reveal their shiny silver underside) has either seen or has taken a ride on the cable car that goes up the mountain. At the top is a giant Jesus statue (very similar if not identical to the one in Rio; it was actually a gift from Brazil) on a dome that used to be a jail but is now a gift shop, and a protected nature preserve. The people in charge of the nature preserve are trying their best at not only educating the public about native Dominican plants, but also conserving habitat suitable for plants that are incredibly rare worldwide. This species of staghorn fern, while not currently at risk for extinction, is becoming more and more rare due to wild harvesting for the gardening industry. The other danger to any Platycerium species is that they are a type of plant called an epiphyte. This is a plant that cannot live on the ground, and instead needs to live on the side of another plant. This doesn't mean that the epiphyte causes the host any harm; in fact, there is no competition for resources between the two plants at all. The host is merely a "prop" to hold the epiphyte off the ground. With tropical forest destruction occurring at an alarming rate worldwide, the available hosts for any epiphyte (which are incredibly common in the tropics) is becoming a scarcity. The sign in the top photo says "do not touch the plants," and there was actually a representative from the nature preserve that was watching all of the tourists like a hawk to make sure no one touched anything. Aside from staghorn ferns, there were incredibly rare orchids (not in bloom, unfortunately) that were also planted there. If someone had of unknowingly picked them, they might have successfully wiped out the only remaining viable population. That might seem like punishment enough, but that would also come with jail time in most tropical countries. Don't pick the plants!

All ferns are vascular plants, which means they contain phloem and xylem to transports nutrients and water throughout the plant (unlike mosses, liverworts and hornworts, which are non-vascular; you can read about the only profiled non-vascular plant, Marchantia, on my blog so far HERE). They reproduce through the production of spores, not seeds, which need to find a suitable habitat to germinate or else they die. Seeds were a great invention by the plant world; this allows plants to create offspring in less than ideal circumstances and let them go dormant in the soil (or a crevasse of a tree, on a leaf, in a compost pile, etc.) until conditions are suitable for germination. Seeds also have nutritive tissue packaged inside them which gives the plant embryo a sugar, protein and fat kick-start which spores can't provide.