3. Pteris Linnaeus, Sp. Pl. 2: 1073. 1753; Gen. Pl. ed 5, 484. 1754.
Brake [Greek pteris, fern, derived from pteron, wing or feather, for the closely spaced pinnae, which give the leaves a likeness to feathers]
Clifton E. Nauman
Plants terrestrial or on rock. Stems erect or creeping, branched; scales pale brown to black, concolored, elongate, margins entire. Leaves monomorphic, clustered or closely spaced, 1--20 dm. Petiole straw-colored, green, brownish red to purple black, longitudinally ridged, 2--3-grooved adaxially, scaly at base, glabrous or scaly distally, with 1 (less often 2 or more) vascular bundle. Blade oblong to lanceolate to deltate, 1--4-pinnate, herbaceous to leathery, abaxially and adaxially glabrous or sometimes pubescent or scaly, adaxially dull, not striate; rachis straight. Ultimate segments of blade sessile to short-stalked, linear to oblong-lanceolate, 1.5--8 mm wide; base truncate or narrowed to stalk, stalk when present green, not lustrous; margins plane or reflexed to form false indusia. Veins in leaves conspicuous, free (except in sori) and forking well above base of segment, or highly anastomosing. False indusia pale, scarious, covering sori. Sporangia intramarginal, sori usually continuous except at pinna or segment apex and sinuses, paraphyses present. Spores brown, trilete, tetrahedral, rugate and/or tuberculate, usually with prominent equatorial flange. x = 29.
Species ca. 300 (5 species and 1 hybrid in the flora): worldwide, warm and tropical regions.
SELECTED REFERENCES
Kramer, K. U. 1990. Pteris. In: K. Kubitzki et al., eds. 1990+. The Families and Genera of Vascular Plants. 1+ vol. Berlin etc. Vol. 1, pp. 250--252. Lakela, O. and R. W. Long. 1976. Ferns of Florida. Miami. Wagner, W. H. Jr. and C. E. Nauman. 1982. Pteris ×delchampsii, a spontaneous fern hybrid from southern Florida. Amer. Fern J. 72: 97--102. Wunderlin, R. P. 1982. Guide to the Vascular Plants of Central Florida. Tampa.
