Thelypteris serra (Sw.) R.P.St.John ex Small
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Authority
Proctor, George R. 1989. Ferns of Puerto Rico and the Virgin Islands. Mem. New York Bot. Gard. 53: 1-389.
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Family
Thelypteridaceae
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Scientific Name
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Description
Species Description - Rhizome wide-creeping, 5-12 mm thick, with stipe bases usually 2-4 cm apart, clothed especially toward apex with light brown to castaneous, lance-attenuate, pubescent scales 3-5 mm long; similar scales on stipe bases. Fronds arching, up to 2 m long; stipes mostly 25-90 cm long, straw-colored or pale brown, usually glabrous at maturity. Blades usually 35-100 cm long, 20-70 cm broad, abruptly reduced at apex to an elongate, nanow, terminal pinna usually 10-30 cm long, 0.6-2.5 cm wide near the base, often at least ten times longer than wide; rhachis pubescent and often bearing small castaneous, lanceolate scales; pinnae subopposite or some of them altemate, spaced 2 cm or more apart on the same side, linear-attenuate, oblique and more or less falcate; largest pinnae usually 15-35 cm long, at least 12 times longer than wide, 6-10(-15) cm broad, crenately lobed or subpinnatifid to a little more than half their width, sessile or nearly so, usually somewhat reduced at base and never with basal auricles or elongate basal segments; basiscopic segments of distal pinnae adnate to rhachis; lobes or segments more or less deltate-falcate with revolute margins; costae with numerous nanow brown scales on abaxial side, these mostly 0.7-1 mm long and 2-5 cells wide, with ciliate margins; veins mostly 4-12 pairs, simple, the basal pair of adjacent segments upcurved and connivent at the sinus; entire underside of blade puberulous beneath, the hairs mostly less than 0.2 mm long; glands absent from both sides of blade, Sori essentially medial; indusium orbicular- reniform, densely hairy; sporangial stalks without glands.
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Discussion
Basionym. Polypodium serra Swartz, Prodr. 132. 1788.
Type. Swartz, from Jamaica (S; isotypes SBT; Herb. Thunb. 24712, UPS; Herb. Willd. 19768, B).
Syn. Aspidium serra (Swartz) Swartz, J. Bot. (Schrader) 1800(2): 33. 1802.
Nephrodium serra (Swartz) Desvaux, Mem. Soc. Linn. Paris 6: 253. 1827.
Lastrea serra (Swartz) K. Presl, Tent, pterid. 75, 1836.
Bryopteris serra (Swartz) Kuntze, Revis. gen. pl. 2: 813. 1891.
Cyclosorus serra (Swartz) Farwell, Amer, Midi. Nat. 12:259. 1931.
Christella serra (Swartz) Pichi Sermolli, Webbia 31:252. 1977.
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Distribution
General Distribution. Greater Antilles. Distribution in Puerto Rico. Confined to the northwestem part of the island; recorded from Arecibo, Camuy, Isabela, Lares, Quebradillas, and San Sebastian. To be expected in Hatillo and Utuado. Habitat. Open banks, pastures, partly-shaded hillsides, and sides of gullies, always associated with limestone, at low to middle elevations (15-300 m), locally frequent.