Thelypteris dentata |
Thelypteris noveboracensis |
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downy maiden fern, downy shield fern, tapering tri-vein fern |
fougère de New York, New York fern, thélyptéride de New York |
|
Stems | short-creeping, 4–6 mm diam. |
usually long-creeping, 1.5–2.5 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, mostly evenly spaced 1 cm or more (sun-gathering leaves in loose cluster), (25–)40–85 cm. |
Petiole | often purplish brown, 15–50 cm × 3–6 mm, at base with brown, linear-lanceolate, hairy scales. |
straw-colored, 4–25 cm × 1–3 mm, at base with scales tan to reddish brown, ovate, glabrous. |
Blade | (25–)40–100 cm, 1–4(–6) proximal pairs of pinnae reduced, blade gradually tapered to pinnatifid apex. |
elliptic, 15–60 cm, proximal 4–10 pinna pairs gradually smaller toward base (smallest often less than 5 mm), blade tapering 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 within 1 mm of costa, 3–9(–13) × 1–2(–2.5) cm; segments oblong to linear, somewhat oblique, entire to crenulate; 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, supramedial; indusia tan, often ciliate; 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 moderately to densely set hairs to 1 mm on rachises, costae, and veins, glands lacking or yellowish to light orangish, mostly sessile on blade tissue; blades adaxially often with hairs on veins. |
2n | = 144. |
= 54. |
Thelypteris dentata |
Thelypteris noveboracensis |
|
Habitat | Damp woods | Terrestrial in moist woods, especially near swamps, streams, and in vernal seeps of ravines, often in slightly disturbed secondary forests, frequently forming large colonies |
Elevation | 0–100 m (0–300 ft) | 0–1100 m (0–3600 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] |
AL; AR; CT; DC; DE; GA; IL; IN; KY; LA; MA; MD; ME; MI; MS; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; VA; VT; WV; NB; NF; NS; ON; PE; QC; SPM
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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.) |
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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 | Polypodium noveboracense, Dryopteris noveboracensis, Parathelypteris noveboracensis, T. thelypterioides |
Name authority | (Forsskål) E. P. St. John: Amer. Fern J. 26: 44. (1936) | (Linnaeus) Nieuwland: Amer. Midl. Naturalist 1: 225. (1910) |
Web links |