Prodr. Aethéogam. 106, 112. 1805.
Aerial shoots to 50 cm, 4 mm diam. at base. Appendages 0.7–2.5 mm (sterile), 1–1.5 mm (fertile). Synangia yellowish to greenish yellow, 2–3 mm wide.
Habitat: Low to mesic woods, thickets, swamps, hammocks, rocky slopes
Elevation: 0–50 m (1100 m in Ariz.)
Ala., Ariz., Fla., Ga., La., Miss., S.C., Tex., Mexico, West Indies in the Antilles, Central America, South America, tropical Asia, tropical Africa.
Reports of Psilotum nudum in New Mexico and in west Texas remain unverified. A wide range of chromosome numbers on material outside the flora has been reported for this species: n =ca.46–56, 104, 210. Most counts, however, are based on n =52 (reviewed in P.J. Brownsey and J.D. Lovis 1987). No count is available from North American material.
Psilotum nudum occurs as a minor weed in greenhouses. Many horticultural forms—including one without appendages and with terminal synangia (A.S. Rouffa 1971)—are grown, especially in Japan.