Thelypteris dentata |
Thelypteris patens |
|
---|---|---|
downy maiden fern, downy shield fern, tapering tri-vein fern |
grid-scale maiden fern |
|
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. |
|
Sori | round, medial to supramedial; indusia tan, pubescent, hairs 0.1–0.3 mm; sporangial stalks with orangish, stalked glands. |
|
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. |
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2n | = 144. |
|
Thelypteris dentata |
Thelypteris patens |
|
Habitat | Damp woods | |
Elevation | 0–100 m (0–300 ft) | |
Distribution |
AL; FL; GA; KY; LA; s Mexico; West Indies in the Antilles; South America to n Argentina; native to tropical and subtropical Asia; Africa [Introduced in North America] |
FL; s Mexico; Central America; West Indies in the Antilles; South America to s Brazil and n Argentina |
Discussion | Thelypteris dentata probably does not persist northward in areas (such as Kentucky) where winters are sometimes severe (R. Cranfill 1980). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 3 (1 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 2. | FNA vol. 2. |
Parent taxa | Thelypteridaceae > Thelypteris > subg. Cyclosorus | Thelypteridaceae > Thelypteris > subg. Cyclosorus |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Polypodium dentatum, Christella dentata, Cyclosorus dentatus, Dryopteris dentata, Dryopteris mollis, T. reducta | Polypodium patens, Christella patens, Cyclosorus arcuatus, Dryopteris patens |
Name authority | (Forsskål) E. P. St. John: Amer. Fern J. 26: 44. (1936) | (Swartz) Small: Ferns S. E. States 243. (1938) |
Web links |