Family

Thelypteridaceae

Nomenclature

Cyclosorus penangianus (Hook.) Copel., Gen. Fil.: 143. 1947. – Polypodium penangianum Hook., Sp. Fil. 5: 13. 1863. – Abacopteris penangiana (Hook.) Ching, Bull. Fan Mem. Inst. Biol. 8: 255. 1938. – Thelypteris penangiana (Hook.) C.F.Reed, Phytologia 17: 303. 1968; Tagawa & K.Iwats., Acta Phytotax. Geobot. 26: 170. 1975; Tagawa & K.Iwats., Fl. Thailand 3: 408, f. 41.2, 42.4–5. 1988. – Pronephrium penangianum (Hook.) Holttum, Blumea 20: 110. 1972; Boonkerd & Pollawatn, Pterid. Thailand: 227. 2000.

Nephrodium costatum Bedd., Ferns Brit. India: t. 220. 1867; Bedd., Handb. Ferns Brit. India: 275. 1883; Bedd., Suppl. Ferns Brit. Ind.: 73. 1892.

Description

Rhizome creeping; scales oblong to oblong-lanceolate with acute apex, up to 7 by 2.5 mm, brown, glabrous, or with marginal hairs. Stipes stramineous with dark base, up to 60 cm long, sparsely scaly at base, glabrescent upwards. Laminae oblong-lanceolate, up to 60 by 25 cm, imparipinnate with 15–20 pairs of lateral pinnae, basal pinna more or less reduced; lateral pinnae straight, ascending, shortly petiolate, narrowly lanceolate, caudately acuminate at apex, cuneate at base, up to 15 by 2 cm, submucronate, serrate at margin; lobes indistinct in appearance but separated by prominent callous membrane at sinus often forming sinus-teeth by callous membrane, costa and costules raised beneath, veins 7–9 pairs, distinct, glabrous or very sparsely minutely hairy. Sori medial, exindusiate; sporangia not setose .

Distribution in Thailand

SOUTH-WESTERN: Kanchanaburi.

Wider Distribution

Himalaya, to S and SW China.

Ecology

Along streams in rather dry valley-forests at about 150 m alt.

Proposed IUCN Conservation Assessment

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

Notes

The specific epithet is derived from the name on a Wallich specimen, though it has been suggested this is erroneous (Holttum 1972).