Aniceto Mendoza

Comparative Research of Gametophytes of Olfersia alata and Olfersia cervina (Dryopteridaceae)

Abstract The prothallial development of gametophytes of Olfersia alata and Olfersia cervina (Dryopteridaceae) is described and compared. Spores are monolete, ellipsoid, and with broadly winged perispore. Germination is Vittaria-type and the prothallial development is Aspidium-type. Adult gametophytes are cordiform-spatulate to cordiform-reniform, with marginal and superficial trichomes. Gametangia are of the type commonly found on leptosporangiate homosporous ferns. Differences between the two species of genus include size of the spores, width of the perispore, germination time, size of the trichomes, and time of formation of the gametangia. These two species share some features with some species of Arachniodes, Cyrtomium, Dryopteris, Phanerophlebia, and Polystichum, such as type of germination and prothallial development and trichomes. They differ from Didymochlaena truncatula, which has prothallial development of the Adiantum-type and lacks trichomes on the sexual phase.

Development of the Sexual Phase of Pseudocolysis bradeorum (Polypodiaceae)

Abstract The development and morphology of the sexual phase of Pseudocolysis bradeorum (Polypodiaceae) are described from material collected in Finca La Selva, near Puerto Viejo, Province of Heredia, Costa Rica. Spores were sown in Thompson medium with agar (25 Petri dishes) and germinated after seven days; the germination pattern was Gleichenia-type and the prothallial development Drynaria-type. Gametangia were typical of homosporous leptosporangiate ferns. Sporophytes appeared after seven months of culture. The sexual phase of this species shares many morphological characteristics with Old and New World species of Polypodiaceae. There is a tendency for vegetative propagation with Pseudocolysis gametophytes.

Comparative Studies of the Gametophytes of Five New World Species of Tectaria (Tectariaceae)

Abstract The gametophyte development and morphology of five Mexican species of Tectaria were documented and compared with what is know from literature reports of the Old world species of Tectaria. Both Old and New World species had the following characteristics in common: spores monolete, ellipsoidal and with a rugose surface; the perine is folded, brown to dark brown, with wing-like folds, and the laesurae measure 1/2 to 3/4 the length of the spore. The germination pattern is of the Vittaria-type and the developmental pattern of the prothallus is of the Aspidium-type. Gametangia are of the common type for the advanced leptosporangiate ferns. The presence of multicellular uniseriate hairs on the gametophytes may represent a synapomorphy for the family.