Plants terrestrial, sometimes epiphytic. Aerial shoots often clumped, simple proximally, dichotomously branched distally, 3(--several)-ridged. Appendages minute, bractlike, borne distally on ridges of aerial shoots, sterile appendages subulate, those subtending synangia 2-lobed. Synangia ± globose, obscurely 3-lobed.

PLANT: perennial, epiphytic, or rarely terrestrial. RHIZOMES: short and creeping in habit, lacking roots but with short hair-like rhizoids. STEMS: green, unbranched basally and dichotomously branching distally; branches angular in crosssection. LEAVES: absent or reduced and lacking veins, 1-2 mm long, alternate, and widely spaced. SYNANGIA: sessile with three valvate lobes dehisching loculicidally. 2 species and 1 natural hybrid; pantropical. (Name from Greek, psilos, naked, referring to the plant's leafless aerial shoots.) REFERENCES: Raul Gutierrez Jr., 2007, Vascular Plants of Arizona: Psilotaceae. CANOTIA 3 (2): 32-34.