Psilotaceae

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.

PLANTS: perennial, terrestrial, epipetric, or epiphytic. ROOTS: lacking. STEMS: green, simple or dichotomously branching. LEAVES: absent or ligulate, less than 1.5 cm long, alternate to subopposite, veinless or with one vein. SYNANGIA: a structure composed of three fused homosporous sporangia, solitary and sessile. SPORES: numerous and reniform. GAMETOPHYTES: subterranean, elongate, and branched. NOTES: 2 genera, 12 spp. Tropical and subtropical areas worldwide, though absent from dry areas. REFERENCES: Gutierrez, Raul, Jr.Vascular Plants of Arizona: Psilotaceae. CANOTIA 3 (2): 32-34, 2007.