1. Cheiroglossa palmata (Linnaeus) C. Presl, Suppl. Tent. Pterid. 57. 1845.
Ophioglossum palmatum Linnaeus, Sp. Pl. 2: 1063. 1753
Roots tan, to 15 per plant, 1--1.5 mm diam., proliferating in humus or underneath palm leaf bases. Stems 0.5--1.5 cm, covered near apex with dense tuft of white to light brown, multicellular hairs to 7 mm. Trophophore blades green, shiny, to 45 × 30 cm, proximal margins diverging 90°--150° from stalk, with up to 7 rounded to mostly linear, acute lobes; venation complex-reticulate, very coarse, veinlets included in (usually elongate) very large major areoles to 35 × 8 mm, veinlets free or sometimes forming individual secondary areoles; blades firm, herbaceous. Trophophore stalk well defined, 1--2.5 times as long as trophophore blade. Sporophores single and central only on youngest or smallest leaves, normally to 10 per leaf, arising closely spaced from both sides of base of trophophore blade and top of stalk, sporangial clusters 1--7cm × 2.5--3 mm, apiculum absent.
Evergreen. Among leaf bases on palmetto trunks [ Serenoa repens (Bartram) Small], mainly in hammocks and swamps; 0--50 m; Fla.; Mexico; West Indies; Central America; South America; disjunct in Asia in s Vietnam; Africa in Madagascar, Seychelles, and Réunion.
This very remarkable plant is becoming extremely rare in Florida.