3. Cheiroglossa C. Presl, Suppl. Tent. Pterid. 56. 1845.
Hand fern, dwarf staghorn [Greek cheir, hand, and glossa, tongue; in reference to the palmately lobed trophophores and the linear sporophores]
Warren H. Wagner Jr.
Florence S. Wagner
Plants epiphytic. Roots dichotomously divided at wide intervals, pale yellowish to brown, 1--1.5 mm diam., smooth, proliferous. Stems pendent, to 1.5 mm thick but appearing thicker because of persistent leaf bases, gemmae absent. Trophophores arching or pendent, blades stalked, palmately lobed, broadly fan-shaped, to 45 × 30 cm; margins entire; apex rounded to acute; veins anastomosing, major areoles very large, to 35 × 8 mm. Sporophores numerous, to 10, arising on each side of base of trophophore blade and apex of trophophore stalk. Sporangial clusters with sporangia in 2 rows embedded in compact, linear spike, apiculum absent. Gametophytes brown to white, cylindric, repeatedly branched, branches 2--20, 1--4 mm thick, and the whole ± stellate structure sometimes reaching 20 mm.
Species 1 (1 in the flora): very scattered and local in tropics, North America, Mexico, West Indies, Central America, South America, Asia, Africa.
Cheiroglossa , which is sometimes treated as a subgenus of Ophioglossum , is widely divergent from Ophioglossum in many characteristics, including the epiphytic habit, dichotomous roots, hairy stem apex, pendent and very large trophophore, palmately lobed blade, extremely large areoles, sporophores multiple and arising from sides of blade base, and the much branched gametophytes.
