Resumo

MENDOZA, Aniceto; PEREZ-GARCIA, Blanca  e  RIBA, Ramón. Morfogénesis de la fase sexual del helecho Arachniodes denticulata (Dryopteridaceae). Rev. biol. trop [online]. 1999, vol.47, n.4, pp.791-797. ISSN 0034-7744.

Spore morphology and sexual fase development 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 development 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 common type in leptosporangiate homosporous ferns. No sporophytes were observed after 200 days of culture. It is concluded that A. denticulata share common characteristics with A. aristata, A. assamica and species of the genera Cyrtomium, Dryopteris and Polystichum, such as type of spore germination, prothallial development and, in early stages of prothallial growth formation of trichomes. Didymochlaena truncatula differ from those species in prothallial development Adiantum-type and naked prothalli

Palavras-chave : Arachniodes; Dryopteridaceae; gametophytes; morphogenesis; prothallus.