Morfogénesis de la fase sexual del helecho <i>Arachniodes denticulata</i> (Dryopteridaceae)

Abstract

Spore morphology and sexual fase deyelopment of Arachniodes denticulata (Sw.) Ching are described from material collected in states of Hidalgo, Oaxaca and Veracruz, Mexico (one sample from each locality). The spores were sown in Thompson medium with agar (30 Petri dishes). The spores are monolete, with perine, ellipsoid.in shape and non chlorophyllic. The germination is Vittaria-type and the prothallial deyelopment Aspidium-type; the gametophytes are. cordiform-spatulate to cordiform-reniform in shape, with unicellular capitate trichome in margin and surface; rhizoids without chloroplasts; gametangia are the cornmon ty¡Je in leptosporangiate homosporous fems. No sporophytes were observed after 200 days of culture. It is conclQded th!\t A. dentic/!.lata share common characteristics with A. aristata, A. assamica and species of the genera Cyrtomi/!.rrí, Dryopteris and Polystichum, such as type of spore germination, prothallial deyelopment and, in early stages of prothallial growth formatidn of trichomes. Didymochlaena truncatula differ from those species in prothallial deyelopment Adiantum-type and naked prothaIli