The genus Odontosoria (Dennstaedtiaceae, Pteridophyta) in Cuba

摘要

A new species, Odontosoria reyesii, known from a single locality in the province of Guantanamo, eastern Cuba, is described. A brief characterization of the other four species of the genus known from Cuba, an identification key and data on their distribution are added.The species of Odontosoria are terrestrial ferns with a thin, creeping, intricately branched, wiry rhizome, which is densely covered with basifix, filiform to linear-ovate, clathrate, brownish golden to reddish brown, lustrous, translucent scales with afiliform apex and usually a truncated to rounded, entire base. The fronds are rampant and of indefinite growth, 2-4 times pinnate, with the last divisions small, flabelliform, cuneiform, variedly lobulate or cleft. The stipe is usually subwoody, straight, almost cylindrical, glabrous, armed with conical to acicular thorns or smooth (not so in the Antillean species). The rhachises, costae and costules are flexuous, with a thin distal fringe on each side, and with thorns that help the plant to climb in the surrounding vegetation. The pinnae and pinnules are numerous, deltate, ovate to linear and shortly petiolate, their veins are forked, free, evident or immersed in the laminar tissue, and ending very near to the margin, the apex sometimes being claviform. The sori are situated terminally on the veins of the last segments or lobes; the indusium is an urceolate, obconical structure that opens at the top and is formed by indusial tissue on one side and lamina tissue on the other side. The spores are triplanate, spherical, with almost smooth or finely granular surface.