Pyrrosia angustata (Sw.) Ching

Family

Polypodiaceae

Nomenclature

Pyrrosia angustata (Sw.) Ching, Bull. Chin. Bot. Soc. 1: 49. 1935; Holttum, Rev. Fl. Malaya ed. 1, 2: 143, f. 58. 1955 [‘1954’]; Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 52. 1968; Hovenkamp, Leiden Bot. Ser. 9: 156, f. 24. 1986; Tagawa & K.Iwats., Fl. Thailand 3: 498. 1989; Hovenkamp, Fl. Males., Ser. II, Ferns and Fern Allies 3: 152. 1998; Boonkerd & Pollawatn, Pterid. Thailand: 284. 2000. – Polypodium angustatum Sw., Syn. Fil.: 27, 224. 1806. – Pleopeltis angustata (Sw.) C.Presl, Tent.: 193. 1836; Bedd., Handb. Ferns Brit. India: 351. 1883. – Type: Rottler s.n., s.d. (holo S), ?India, Trankebar.

Description

Rhizome long creeping, 1.5–2.6 mm diam., hard, densely scaly throughout; scales oblong-lanceolate, distinctly bi-coloured, the basal portion dark brown to black, appressed, the apical portion pale brown to stramineous, hairy at margin, patent, caducous, 5–11 by 0.5–1 mm. Fronds simple. Stipes 5–12(–25) cm long, brown, glabrescent. Fronds narrowly lanceolate, 5–44 by 1–4.5 cm, the soriferous apical portion about a half in breadth, entire and more or less involute at margin, cuneate at base, long-acuminate at apex; midrib distinctly raised beneath, a little grooved on upper surface, veins all invisible, copiously anastomosing; thick, leathery, upper surface glabrescent, without hydathodes, lower surface covered with pale stellate hairs with shorter arms. Sori large, up to 10 by 4 mm broad, arranged in one regular row at each side of rachis on apical half of the fronds, usually sunk in shallow hollows, appearing raised on upper surface.

Distribution in Thailand

PENINSULAR: Yala, Narathiwat.

Wider Distribution

Malesia.

Ecology

On tree trunks in light shade at low altitudes.

Proposed IUCN Conservation Assessment

Least Concern (LC). This species is widespread and not under any known threat.

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