Plants terrestrial; branches tufted, erect, without main indeterminate stem; roots all in one basal tuft. Vegetative buds/bulbils produced in axils of fertile leaves. Fertile leaves neither differentiated nor ranked, persisting after sporangia dehisce; sporangia axillary; spores triangular in polar view with concave faces, surface pitted or grooved. Gametophyte subterranean, cylindric, saprophytic.
10–15 species, primarily northern hemisphere temperate, 2 in Australia.