Morfogénesis de la fase sexual de seis especies mexicanas de helechos del género <i>Dryopteris</i> (Dryopteridaceae)

Abstract

The development of the sexual phase of six Mexican species of the fern Dryopteris is described and compared. The spores of all six species are monolete, ellipsoid, the perine is folded, brown to dark brown, with a tubercled outline. The germination pattern of the species is Vittaria-type and the development pattern of the prothallia is Aspidium-type. The gametangia are the common sort for the leptosporangiate advanced ferns, the necks of the archegonia have four rows of cells, with 4-5 cells each and appear 53-218 days after the sowing of the spores. The antheridia appear 46-234 days after the sowing, have three cells surrounding the androgenic cell. The first leaves of the sporophytes appear 60-262 after the sowing and, apparently in D. munchii and D. wallichiana the sporophytes have an apogamic origin.