Cyclosorus penangianus (Hook.) Copel.




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.


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.


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.


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

Site hosted by the Royal Botanic Garden Edinburgh. Content managed by Stuart Lindsay, Gardens by the Bay, Singapore and David Middleton, Singapore Botanic Gardens. Last updated 24 January 2012