Sunday, November 1, 2009

Tuateawa Plant Spot: TMESIPTERIS TANNENSIS, The fork "fern"


This is a fairly common plant in Tuateawa. It is usual to find it growing as an epiphyte on the trunks of tree ferns.It is nothing flash to look at, so most interest revolves around it's status as a living fossil. We consider the Tuatara to be very special. It had it's major flourishing 200 million years ago, but managed to survive when all of it's relatives became extinct 60 million years ago.

This plant goes back about 350 million years, long before Gondwanaland, to the time of the very first supercontinent, Pangea. Its ancestors were among the first plants to develop adaptations to living on the land. They had vascular tissue for moving water and sugars around, a big improvement on the mosses. They lacked true roots and their leaves were small and scale like. Plants continued to evolve with better adaptations, first the ferns and finally the flowering plants which make up current dominant vegetation.

Today most of Tmesipteris relatives are known only from their fossils. Only a few species exist in this far corner of the world, in Tasmania, some parts of Australia and islands like the New Hebrides and others in the Indian Ocean. They still exist because they found a new place to live. On the trunks of one of the plants that replaced them!

No comments:

Post a Comment