Morphological and taxonomical studies inBlechnum(Blechnaceae-Pteridophyta):B. tabulareandB. magellanicum

[摘要] Specimens ofB. tabulareandB. magellanicumfrom their whole geographical area were studied, and taxa were treated as different species. The following characters were analyzed: rhizomes, rhizomatic scales, stipes, division of dimorphic laminae, outline, texture, size, margins, indument, venation, epidermal patterns, stomata (size and density), mesophyll of pinnae in transversal section, mucilaginiferous unicellular glands of axes and laminae, and spores. Habit of plants, type of rhizome, rhizomatic scales, mucilage glands, and type of ornamentation of the perispore are characters shared by the two species, while the other traits vary at the specific level, allowing them to be identified as two separate taxa.Blechnum tabulareis distributed in the tropics and subtropics of South America, África, and Islands of the Atlantic and Indic Oceans, whileB. magellanicumis a subantarctic, more restricted species, that grows in humid areas of Argentina and Chile, South America. New descriptions of both species are given, along with comments on their affinities with other arborescent species of the genus.

[学科分类] 植物学

[关键词] Blechnaceae;Blechnum tabulare;Blechnum magellanicum;taxonomy;sporophyte;spores;geographical distribution