Variable maiden fern, St. John's shield fern

Thelypteris versicolor R. P. St. John in Small, Ferns S.E. States, 250, plate. 1938; Dryopteris versicolor (R. P. St. John) Broun; Thelypteris macilenta E. P. St. John; T. quadrangularis (Fée) Schelpe var. versicolor (R. P. St. John) A. R. Smith

Stems short-creeping to ascending at apex, 3--5 mm diam. Leaves monomorphic, evergreen, closely placed, (20--)40--95 cm. Petiole straw-colored, (5--)10--40 cm × 1.5--3 mm, at base with brown, lanceolate, hairy scales. Blade 14--55 cm, proximal 0--2(--4) pairs of pinnae slightly to greatly reduced (lowest pinnae to 1/3 length of longest), blade gradually tapered to pinnatifid apex. Pinnae 4--14 × 0.8--2 cm, incised 3/4--4/5 of width; segments spreading or somewhat oblique, rounded at tip, basal acroscopic segment of proximal pinnae sometimes auriculate and crenate; proximal pair of veins from adjacent segments united just below sinus or approaching each other and turning abruptly toward sinus, or connivent at sinus, excurrent vein, if any, 1 mm or less. Indument on both surfaces of densely set hairs 0.2--0.8 mm on costae, veins, and often blade tissue, also often of yellowish, stalked glands 0.1 mm. Sori round, medial to supramedial; indusia hairy; sporangial stalks with inconspicuous stalked, pear-shaped glands. 2 n = 72.

Woodlands and limestone sinks, especially in seepage areas and along streams; 0--100 m; Ala., Fla., Ga., La., Miss., S.C., Tex.; West Indies in Cuba.