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Kunth's maiden fern, southern shield fern, widespread maiden fern

Hottentot fern, spready tri-vein fern, Willdenow's fern, Willdenow's maiden fern

Stems

short- to long-creeping, 4–8 mm diam.

long-creeping, cordlike, 3–6 mm diam.

Leaves

monomorphic, evergreen, up to 2(–3) cm apart, (15–)50–160 cm.

monomorphic, evergreen, 3–6 cm apart, 50–150(–250) cm.

Petiole

straw-colored, (5–)20–80 × (1–)3–6 mm, at base with brown, linear-lanceolate, hairy scales.

straw-colored to tan, 20–125 cm × 3–6 mm, scaleless.

Blade

(9–)30–80 cm, broadest at base, gradually tapered to pinnatifid apex.

30–125 cm, broadest at base, gradually narrowed distally to pinnatifid apex.

Pinnae

(2–)8–15(–20) × (0.6–)1–2.5 cm, incised 3/5–4/5 of width;

segments oblong, rounded to acute at apex;

proximal pair of veins from adjacent segments running to sinus, or nearly so.

7–30 × 1–2 cm, incised 1/3–1/2(–3/5) of width;

segments deltate, rounded to acute;

proximal pair of veins from adjacent segments united at acute or obtuse angle below sinus, with excurrent vein 2–4 mm.

Sori

round, medial to supramedial;

indusia tan, hairy, hairs 0.2–0.4 mm;

sporangial glands obscure, yellowish, stalked, arising from sporangial stalks.

round, medial to supramedial;

indusia tan, glabrous to hairy;

sporangia with red- or orange-capped, stalked, globose glands arising from sporangial stalks.

Indument

abaxially of hairs mostly 0.3–1 mm on costae, veins, and blade tissue;

veins adaxially with similar hairs but blade tissue usually without hairs, often with scattered yellowish, stalked glands 0.1 mm.

abaxially of hairs 0.1–0.3 mm on costae and veins, or hairs often lacking, costae also with tan, ovate scales;

veins, costules, and costae adaxially glabrous or sparsely pubescent;

blade tissue without hairs on both sides, or hairy abaxially, usually with red to orange, shiny, sessile, hemispheric glands abaxially.

2n

= 144.

= 144.

Thelypteris kunthii

Thelypteris interrupta

Habitat Roadsides, ditches, riverbanks, woodlands, limestone sinks Wet roadside ditches, riverbanks, marshes, and cypress swamps
Elevation 0–100 m (0–300 ft) 0–50 m (0–200 ft)
Distribution
from FNA
AL; AR; FL; GA; LA; MS; SC; TX; e,s Mexico; West Indies; Bermuda; Central America to Costa Rica; South America from Colombia to n Brazil
[WildflowerSearch map]
from FNA
FL; LA; Mexico; Central America; West Indies in the Antilles; South America to Argentina; tropical and subtropical Asia; Africa
Discussion

Thelypteris kunthii occasionally hybridizes with T. augescens and T. ovata in Florida; hybrids with T. hispidula may also occur.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

D. B. Lellinger (1985) applied the name Thelypteris interrupta to specimens from India, while using T. totta (type from South Africa) for North American and South American specimens. Diploid cytotypes are known from Africa and Asia, whereas all counts from the Neotropics are tetraploid. Until more counts are available and the morphologic variation (chiefly in glands, pubescence, and leaf size) in this species complex is better understood, I prefer to circumscribe the species broadly.

R. E. Holttum (1982) circumscribed Cyclosorus (as a genus) to include this species and one or two others.

(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
T. augescens, T. dentata, T. grandis, T. hispidula, T. interrupta, T. nevadensis, T. noveboracensis, T. ovata, T. palustris, T. patens, T. pilosa, T. puberula, T. quelpaertensis, T. reptans, T. resinifera, T. reticulata, T. sclerophylla, T. serrata, T. simulata, T. tetragona
T. augescens, T. dentata, T. grandis, T. hispidula, T. kunthii, T. nevadensis, T. noveboracensis, T. ovata, T. palustris, T. patens, T. pilosa, T. puberula, T. quelpaertensis, T. reptans, T. resinifera, T. reticulata, T. sclerophylla, T. serrata, T. simulata, T. tetragona
Synonyms Nephrodium kunthii, Christella normalis, Dryopteris normalis, T. macrorhizoma, T. normalis, T. saxatilis, T. unca Pteris interrupta, Cyclosorus gongylodes, Cyclosorus interruptus, Cyclosorus tottus, Dryopteris gongylodes, T. gongylodes, T. totta
Name authority (Desvaux) C. V. Morton: Contr. U.S. Natl. Herb. 38: 53. (1967) (Willdenow) K. Iwatsuki: Jap. J. Bot. 38: 314. (1963)
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