Tuesday, January 4, 2011

Polystichum falcinellum, inventor of the scythe

Its scientific name pretty much says it all about him in three words, two Greek together and one Latin with a diminutive suffix: Poly-stichos falci-nellum = many-lined scythe-small, ie leaflets as small scythes with many sori in a row. The botanist who named it, Swartz, got summed up in two words what this treasure most striking plant in the world can only be found in the darkest forests and humid high mountain on the island of Madeira.

Beautiful specimen of Polystichum falcinellum intense in the shadows of a pine forest of Monte Poiso at 1450 masl. No flash would have been impossible to photograph. Beside you can see several tender fronds of other Madeiran endemic, the Dryopteris maderensis. (Double click on the photo to enlarge)
It is a distinctive plant with a design so characteristic that, once seen a copy, never to be forgotten. Before traveling to Madeira had seen a picture of him online, but I had forgotten about him and not looking especially. My obsession was to find the Asplenium anceps, ancestral grandfather Macaronesian fern of Asplenium azomanes of Mallorca. Walking and scanning with it the very thick forest that borders the road to the summit of Monte Poiso, my attention these dark fronds in the shadows are almost black. Were covered with dry branches and pine litter fall. Nothing more to see their leaflets in the form of small scythes knew I had found one of the rarer endemic flora of Madeira.

Frond of the previous issue so characteristic falcate pinnae. In the proximal part of the rachis beam are paleae as brown hairs, which are more abundant on the underside of the frond.

In this picture you can see the falcate pinnae as small scythes or sickles, attached to the rachis for a short petiole. They draw attention to the two auriculae of the base, the largest facing the apex of the lamina. (Double click on the photo to enlarge)

Details of the two basal auriculae above pinnae.

This image justifies the name gave it the botanist Swartz: leaflets with form of small scythes with many sori in a row. Here we can see better the paleaceous pilosities of the rachis consisting of dry cells and the two auriculae of the base of the pinnae, the greater the apical to the proximal, each with several sori on their back.

Paleae detail of the rachis, the two auriculae of the base of the pinnae and sori covered by an indusium stuck on the umbrella-shaped center (peltate), which are arranged in two rows along the midrib of the pinna, distribution repeated in the auricula.
The Polystichum falcinellum is easy to hybridize with Polystichum setiferum, leading to a beautiful hybrid with a medial aspect, the Polystichum x maderense.

Image of Polystichum x maderense hybrid, taken from the excellent website of Andrew Leonard. Hybridization has made that the basal auricula of the pinnae are transformed into two petiolate pinnules.  Andrew Leonard´s Fern Site

No comments:

Post a Comment