Thelypteris dentata |
Thelypteris simulata |
|
---|---|---|
downy maiden fern, downy shield fern, tapering tri-vein fern |
bog fern, Massachusetts fern, thélyptère simulatrice |
|
Stems | short-creeping, 4–6 mm diam. |
long-creeping, 1.5–3 mm diam. |
Leaves | often somewhat dimorphic, evergreen, often closely placed, 50–150 cm, fertile leaves with longer petioles and more contracted pinnae. |
monomorphic, dying back in winter, often 1 cm or more apart, fertile leaves often somewhat longer than sterile leaves, 25–80 cm. |
Petiole | often purplish brown, 15–50 cm × 3–6 mm, at base with brown, linear-lanceolate, hairy scales. |
straw-colored above base, 12–45 cm × 1–3 mm, at base sparsely set with tan, ovate, glabrous scales. |
Blade | (25–)40–100 cm, 1–4(–6) proximal pairs of pinnae reduced, blade gradually tapered to pinnatifid apex. |
lanceolate, 14–35 cm, proximal pinnae largest, or lowest pair slightly smaller, blade tapered gradually 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. |
deeply pinnatifid to ca. 1 mm from costa, 3–10 × 1–2 cm; segments oblong, somewhat oblique, entire; proximal pair of veins from adjacent segments meeting margin above sinus. |
Sori | round, medial to supramedial; indusia tan, pubescent, hairs 0.1–0.3 mm; sporangial stalks with orangish, stalked glands. |
round, medial; indusia tan, often glandular; sporangia glabrous. |
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. |
abaxially of sparsely set hairs 0.2–0.4 mm primarily on costae, also of yellowish short-stalked glands less than 0.1 mm, blade tissue with numerous reddish to orangish, resinous, shiny, sessile, hemispheric glands; blades adaxially with scattered hairs on veins. |
2n | = 144. |
= 128. |
Thelypteris dentata |
Thelypteris simulata |
|
Habitat | Damp woods | Terrestrial in acid soils of shaded swamps and bogs, frequently associated with sphagnum |
Elevation | 0–100 m (0–300 ft) | 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] |
CT; DE; MA; MD; ME; NH; NJ; NY; PA; RI; VA; VT; WI; WV; NB; NS; ON; QC
|
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.) |
|
Source | FNA vol. 2. | FNA vol. 2. |
Parent taxa | Thelypteridaceae > Thelypteris > subg. Cyclosorus | Thelypteridaceae > Thelypteris > subg. Parathelypteris |
Sibling taxa | ||
Synonyms | Polypodium dentatum, Christella dentata, Cyclosorus dentatus, Dryopteris dentata, Dryopteris mollis, T. reducta | Aspidium simulatum, Parathelypteris simulata |
Name authority | (Forsskål) E. P. St. John: Amer. Fern J. 26: 44. (1936) | (Davenport) Nieuwland: Amer. Midl. Naturalist 1: 226. (1910) |
Web links |