A COMPARATIVE-STUDY OF GAMETOPHYTE MORPHOLOGY, GAMETANGIAL ONTOGENY AND SEX EXPRESSION IN THE ASPLENIUM-ADIANTUM-NIGRUM COMPLEX (ASPLENIACEAE, PTERIDOPHYTA)

Spores from two diploid taxa, Asplenium onopteris L, and A. cuneifoliu m Viv., and two allotetraploid taxa, A. adiantum-nigrum L, var. adiant um-nigrum and A. adiantum-nigrum var. silesiacum (Milde) Viane & Reich stein, were cultured in three different types of soil. Except for A. c uneifolium, the spores germinated after ten days. The general pattern of development for the gametophytes was similar in all four taxa, foll owing the Aspidium-type. We found that the length and density of margi nal hairs differ at the specific level. The formation sequence of the gametangia studied in the three Iberian taxa was the same, and is inde pendent of the soil type. Our results indicate that the spores in this group of taxa are able to germinate and develop mature gametophytes i n different kinds of soil, and that they can produce sporophytes.