Family

Thelypteridaceae

Nomenclature

Thelypteris flaccida (Blume) Ching, Bull. Fan Mem. Inst. Biol. 6: 336. 1936; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 366. 1941; Tagawa & K.Iwats., Aata Phytotax. Geobot. 25: 16 1971; Tagawa & K.Iwats., Fl. Thailand 3: 399. 1988. – Aspidium flaccidum Blume, Enum. Pl. Javae.: 161. 1828. – Lastrea flaccida (Blume) T.Moore, Index Filic.: 92. 1858; Bedd., Handb. Ferns Brit. India: 244 f. 125. 1883. – Metathelypteris flaccida (Blume) Ching, Acta Phytotax. Sin. 8: 306. 1963; Holttum, Fl. Males., Ser. II, Pterid. 1: 351, f. 3e–f. 1982 [‘1981’]; Boonkerd & Pollawatn, Pterid. Thailand: 224. 2000. – Type: Blume, Boerangrang, Java (L sheet 908,332-1093).

Description

Rhizome short, erect; scales narrow, thin and usually crisped, up to 5 by 0.8 mm, brown, hairy on dorsal surface and at margin. Stipes up to 20 cm long., stramineous to pale castaneous, scaly on basal portion, hairy throughout. Laminae oblong-lanceolate, pinnate-bipinnatifid, up to 40 by 15 cm; pinnae about 5 cm apart, falcate, basal one or two smaller, all sessile, middle larger ones lanceolate, acuminate at apex, up to 8 by 2 cm; costa hairy throughout, winged; pinnules patent, narrowly oblong, rounded at apex, decurrent at base towards the wings of costa, deeply lobed to 2/3 way towards costule, up to 10 by 5 mm; lobes oblong to subdeltoid, moderately acute at apex, serrate; papyraceous, green; veins pinnate, veinlets usually forked, not reaching the very margin of lobes; hairs all unicellular, simple, patent or sometimes hooked on laminar surface. Sori dorsal on veinlets, medial; indusia caducous, small, pale brown, hairy .

Distribution in Thailand

NORTH-EASTERN: Phetchabun.

Wider Distribution

Sri Lanka, India, SW China (Yunnan and Guizhou), N Vietnam, and Java.

Ecology

On half-shaded, humus-rich banks of new road at about 1200 m alt.

Proposed IUCN Conservation Assessment

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