Gigaspermum Lindb.

Plants gregarious, pale, yellow-, white-, or dark green, occasionally silvery. Primary stems subterranean and hyaline, freely and irregularly branched, leafless, with pale, smooth rhizoids; shoots erect, budlike or ± elongate (to at least 5 mm), densely foliate, in cross-section with an indistinct central strand surrounded by undifferentiated parenchyma cells. Leaves erect, small below, larger above, to 2.5(–3.5) × c. 1.0 mm, broadly ovate, gradually subulate-acuminate at apex, yellow- or dark green, occasionally hyaline in upper portions; margins entire or nearly so; laminal cells rectangular to oblong-rhombic, moderately thin-walled, neither undulate nor thickened at corners. Costa lacking.

Autoicous (antheridia variably distributed but not synoicous). Perichaetial leaves much enlarged and enclosing the sessile capsule. Perigonia usually terminal on well-developed, erect, male branches; antheridia small, mixed with filiform paraphyses. Setae extremely short, pale; capsules immersed, pale yellow-brown, ± globose, wide-mouthed, spongy and strongly wrinkled when dry; exothecial cells oblong-hexagonal; stomata 2-celled; operculum broad and flat, minutely and obscurely apiculate. Calyptra minute, conic-mitrate. Spores extremely large, brown, sometimes appearing angular, densely papillose.

A small genus of probably only two species. It is distributed in Australasia, northern and southern Africa, the Mediterranean and Macaronesian regions, and Mexico. Gigaspermum repens occurs in N.Z.