Plants perennial, terrestrial or epiphytic, with corallike, rhizoid-bearing, branched, subterranean axes. Roots absent. Aerial shoots simple or dichotomously branched; appendages leaflike or bractlike, alternate to subopposite, veinless or 1-veined, less than 1 cm. Synangia globose, of 2--3 fused, homosporous eusporangia, solitary in axils of shoot appendages, dehiscing loculicidally. Spores many, reniform, not green. Gametophytes subterranean, mycotrophic, fleshy, elongate, and branched.