XVI International Botanical Congess

Spores of Spheropteris lepifera and Alsophila spinulosa maintained germination rates of over 90% for two year's storage at 40C. Development was of Adiantum-type to Drynaria-type for both species. The mature gametophytes were heart shaped, with some elongating with age. Gametophyte regeneration was found in the older gametophytes of both species. Antheridium formation by these species was not promoted by the presence of mature gametophytes of Pteridium aquilinum, Lygodium japonicum and Ceratopteris thalictroides or by older gametophytes of their own species. Neither did their spores germinate in darkness under these treatments. These results indicate that there is no antheridiogen activity in these two species. The gametangial sequence of their gametophytes also did not fit the model of antheridiogen action.