Looking for morphological evidence to a phylogenetic generic delimitation in Ophioglossaceae

ESTEBAN MEZA TORRES

Washington

Congreso; 13th Smithsonian Botanical Symposium 12th Symposium of the International Organization of Plant Biosystematist "Pteridology, next generation"; 2015

American Fern Society

The family Ophioglossaceae R.Br. is characterized mainly by presenting a frond divided into two parts, a fertile one which carries the sporangia, called the sporophore, and another sterile called trophophoro. This family has probably 55-70 species worldwide. The generic systematic level is very variable according the different authors, recognizing between four to seven genera. A widely used criterion recognizes only the genera Botrychium Sw., Helminthostachys Kaulf. Mankyua B.Y.Sun, M.H.Kim & C.H.Kim, and Ophioglossum L. Recently, molecular phylogenetic analysis has resulted in groups of species that can be delimited in monophyletic genera. But, what genera should be used to denominate the resulting clades, and which morphologic characters could characterize these genera? Based on morphological characters, seven genera are proposed, which are consistent with clades. The genera related to morphological characters that support the delimitation are: Botrychium: glabrous plants, free venation with a degree of anastomosis in the veins near the rachis; Botrypus: contractile-like roots, with lateral branchings in monopodial like pattern, rudimentarily circinate or bent vernation, leaf hairy, at least on primordia stage, forked venation, without anastomoses or not; Helminthostachys: pinnate, parallel 1-forked venation; Mankyua: angiostroma branched 1 or 2 time near base, almost sessile; Ophioderma (Blume) Endl.: epiphytic plants, roots with dichotomous branches, rhizomatic indumentum with articulate, branched, and brown hairs, leaf blade furcate, multiple angiostromas for sporophore; and Ophioglossum: unbranched roots, conduplicate, moderate circinate vernation, entire leaves, single angiostroma for sporophore. The names Botrypus and Ophioderma should be used by priority principle.