Trop picks: Spanish Moss

Today's arrangement features members of the much misunderstood Tillandsia family, both the Tillandsia usneoides (Spanish moss) and Tillandsia caput medusae (Medusa's head).

The Tillandsia is sometimes called an airplant, with the implication that it needs nothing but air to survive. After all, it doesn't have roots.

It's also why the Swedish taxonomist Carl Linnaeus named the Tillandsia after a colleague, Elias Tillandz. Tillandz, as a student crossing the waters directly from Stockholm to Turku in Sweden, was so seasick that he got off the boat, turned around and walked back over land to Stockholm, a journey of a thousand miles. Thus he acquired his surname--"Tillandz" or "by land." Linnaeus thought that like Tillandz, the Tillandsia did not like water, since it somehow survived despite the absence of roots.

Later scientists discovered that the Tillandsia did need water to survive, but they figured (with a tinge of bigotry perhaps) that it didn't get the water it needed through honest labour of its own. After all, it didn't have roots.

Instead, they thought, it lived parasitically off the labour of big and strong trees. And no sooner would the Tillandsia settle in a tree than the little sucker would suck the life right out of its host. To wit, the many dead branches where it made its home.

The mistake here was to confuse cause and effect. Yes, the Tillandsia does live on the dead limbs of tall trees, but the reason for that is simple. The Tillandsia prefers sunny exposures, which means it avoids trees with shade. Many trees, when in perfectly healthy condition, have too dense a foliage to serve as a host for the Tillandsia, but if for some reason — preceding the arrival of the Tillandsia — the foliage is reduced, the light conditions become more favourable to the Tillandsia. The plant then merely wraps its stems around the branches of the tree for support and not for nourishment.

A plant that is rootless, much like a human being, still needs air and water--it's just that it gets it in alternative ways and not necessarily by taking from others. The tiny, closely overlapping leaf-scales of the Tillandsia, which are responsible for the apparently grey colour since they reflect light, have assumed the function of water absorption from rain, mist or dew. They are why the Tillandsia does so well in very humid environments like our own.