Sexual phase morphogenesis of six Mexican fern species (Dryopteris) (Dryopteridaceae)

The development of the sexual phase of six Mexican species of the fern Dryo pteris is described and compared. The spores of all six species are monolet e, ellipsoid, the perine is folded, brown to dark brown, with a tubercled o utline. The germination pattern of the species is Vittaria-type and the dev elopment pattern of the prothallia is Aspidium-type. The gametangia are the common sort for the leptosporangiate advanced ferns, the necks of the arch egonia 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. mu nchii and D. wallichiana the sporophytes have an apogamic origin.