Gametophytes of Lycopodium digitatum (Formerly L. Complanatum var. flabelliforme) as Grown in Axenic Culture

Abstract

The spores of Lycopodium digitatum only germinate in the dark, and the gametophytes grow from spores in axenic culture on a medium containing inorganic nutrients and sucrose. Dark-grown prothalli develop into white, carrot-shaped gametophytes with a tapering base, constricted neck, and gametangial cap. The antheridia are large and sunken, and the archegonia have long necks with numerous neck canal cells. Although these gametophytes lack an endophytic fungus, the tapering base has a zone of radially elongated cells that is comparable to the inner mycorrhizal zone of the gametophytes from nature. Gametophytes grown in the light turn green, but their morphology remains stable. The endophyte-free gametophytes from culture are remarkably similar to gametophytes of L. digitatum from nature.