Cyclosorus sakayensis (Zeiller) Ching




Cyclosorus sakayensis (Zeiller) Ching, Bull. Fan Mem. Inst. Biol. Bot. 10: 248. 1941. – Nephrodium sakayense Zeiller, Bull. Soc. Bot. France 32: 75. 1885. – Thelypteris sakayensis (Zeiller) C.F.Reed, Phytologia 17: 311. 1968. – Sphaerostephanos sakayensis (Zeiller) Holttum in B.K.Nayar & S.Kaur, Companion Handb. Ferns Brit. India: 209. 1974. – Chingia sakayensis (Zeiller) Holttum, Fl. Males., Ser. II, Pterid. 1: 392, f. 8c–e. 1982 [‘1981’]. – Type: De Morgan s.n., 6 Aug. 1884, near Gunong Riam, Perak. 750 m (P; K).

Chingia pseudoferox Holttum, Kalikasan 3: 24. 1974.

Cyclosorus ferox auct. non (Blume) Ching: Holttum, Rev. Fl. Malaya ed. 1, 2: 265, f. 51. 1955 [‘1954’]. – Thelypteris ferox auct. non (Blume) Tagawa & K.Iwats.: Tagawa & K.Iwats., Fl. Thailand 3: 403. 1988. – Chingia ferox auct. non (Blume) Holttum: Boonkerd & Pollawatn, Pterid. Thailand: 219. 2000.

Thelypteris paleata auct. non (Copel.) Holttum: Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 53. 1968, pl. 40. 1–3.


Rhizome erect; scales narrow, 11–16(–20) x 1.2–1.5 mm, hairy, brown. Frond gigantic; stipe stramineous(?), to 200 cm; lamina to 200 cm long, to 70 cm wide; rachis glabrous or sparsely scaly with linear hairy scales; middle lateral pinnae linear, 19–40 by 1.6–3.2 cm, gradually narrowing towards long-acuminate apex, narrowing a little towards truncate base, lobed to 1/4 way towards costa; segments oblong-subdeltoid, moderately acute at apex, entire; papyraceous to thinly chartaceous, firm, glabrous; veins pinnate, the lowest meeting with concurrent veinlets, lower several pairs uniting at long callous membrane below sinus. Sori strictly costular, round, usually confluent along costules at maturity; indusia browh, thin, small but persistent, hairy, glandular at margin .

Distribution in Thailand


Wider Distribution



Terrestrial in forests along streams at 160–500 m alt.

Proposed IUCN Conservation Assessment

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

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