Trichomanes

• Authority

  Mickel, John T. & Beitel, Joseph M. 1988. Pteridophyte Flora of Oaxaca, Mexico. Mem. New York Bot. Gard. 46: 1-580.

• Family

  Hymenophyllaceae

• Scientific Name

  Trichomanes

• Description

  Genus Description - Mostly epiphytic, a few terrestrial or epipetric; rhizome usually long-creeping, erect in some species, very slender, with stiff hairs; roots present or absent; fronds minute to small, occasionally mediumsized, generally monomorphic, rarely dimorphic, distant; stipe slender, glabrous or hairy; blade divided to decompound, membranaceous, mostly only one cell thick, glabrous or with simple to stellate hairs (on veins and leaf margin); segments mostly adnate and decurrent to next axis; sori marginal, in conical or tubular involucres with straight or flared, entire to bilobed mouth, immersed in lamina or exserted; receptacle growing from base, resulting with age generally in a long-exserted trichome; spores tetrahedral-globose, green, lacking perispore or any conspicuous markings; ga-metophytes filamentous, often gemmiferous.

• Discussion

  Lectotype (chosen by J. Smith, Hist. fil. 347. 1875): Trichomanes scandens Linnaeus. Didymoglossum Desvaux, Mém. Soc. Linn. Paris 6: 330. 1827. Lectotype (chosen by Christensen, Index filic, xiv. 1906): Didymoglossum muscoides (Swartz) Desvaux [= Trichomanes muscoides Swartz, = Trichomanes hymenoides Hedwig]. For additional synonymy, see Morton (1968). Trichomanes is a pantropical genus of over 300 species, of which about 100 are American, with about 20 in Mexico. The genus was split by Copeland (1938) into many genera, but splitting seems to compound the problem of generic delimitation in the filmy ferns rather than alleviate it. Oaxacan material falls into six of Copeland’s genera. We concur with A. R. Smith’s placement (1981) of T. pyxidiferum into sect. Lacosteopsis; what Morton interpreted as false veins are wrinkles in the lamina. The genus is distinct by its filmy blade, tubular involucre and strongly exserted receptacle. References: Copeland, E. B. 1938. Genera Hymenophyllacearum. Philipp. J. Sci. 67: 1-110; Morton, C. Y. 1968. The genera, subgenera, and sections of the Hymenophyllaceae. Contr. U.S. Natl. Herb. 38: 153214; Wessels Boer, J. G. 1962. The New World species of Trichomanes sect. Didymoglossum and Microgonium. Acta Bot. Neerl. 11: 277-330.