14.
Thelypteris dentata
(Forsskål) E. P. St. John, Amer. Fern J. 26: 44. 1936.
Downy maiden fern, downy shield fern, tapering tri-vein fern
Polypodium dentatum
Forsskål, Fl. Aegypt.-Arab., 185. 1775;
Christella dentata
(Forsskål) Brownsey & Jermy;
Cyclosorus dentatus
(Forsskål) Ching;
Dryopteris dentata
(Forsskål) C. Christensen;
D
.
mollis
(Swartz) Hieronymus;
Thelypteris reducta
Small
Stems short-creeping, 4--6 mm diam. Leaves often somewhat dimorphic, evergreen, often closely placed, 50--150 cm, fertile leaves with longer petioles and more contracted pinnae. Petiole often purplish brown, 15--50 cm × 3--6 mm, at base with brown, linear-lanceolate, hairy scales. Blade (25--)40--100 cm, 1--4(--6) proximal pairs of pinnae reduced, blade gradually tapered to pinnatifid apex. Pinnae 7--17 × 1--3 cm, incised 1/2--3/4 of width; segments rounded at apex, basal acroscopic segment of proximal pinnae often auriculate; proximal pair of veins from adjacent segments united at obtuse angle below sinus with excurrent vein 2--4 mm. Indument abaxially of uniformly short hairs 0.1--0.2 mm on costae, veins, and blade tissue; veins adaxially with stouter hairs, also with hairs 0.1--0.2 mm on blade tissue. Sori round, medial to supramedial; indusia tan, pubescent, hairs 0.1--0.3 mm; sporangial stalks with orangish, stalked glands. 2 n = 144.
Damp woods; 0--100 m; introduced; Ala., Fla., Ga., Ky., La.; s Mexico; West Indies in the Antilles; South America to n Argentina; native to tropical and subtropical Asia, Africa.
Thelypteris dentata probably does not persist northward in areas (such as Kentucky) where winters are sometimes severe (R. Cranfill 1980).
