Family

Thelypteridaceae

Nomenclature

Cyclosorus clarkei (Bedd.) Ching, Bull. Fan. Mem. Inst. Biol. Bot. 8: 178. 1938. – Pleocnemia clarkei Bedd., Suppl. Ferns S. Ind.: 15, t. 368. 1876. – Tectaria clarkei (Bedd.) C.Chr., Index Fil. Suppl. III: 178. 1934. – Thelypteris clarkei (Bedd.) C.F.Reed, Phytologia 17: 268. 1968; Fraser-Jenk., New Sp. Syndr. Indian Pteridol. 259. 1997. – Christella clarkei (Bedd.) Holttum in B.K.Nayar & S.Kaur, Companion Handb. Ferns Brit. India: 203. 1974; Holttum, Kew Bull. 31: 308. 1976. – Type: Clarke 9973, Sikkim, Darjeeling, 1400 m (K).

Dryopteris cylindrothrix Rosenst., Rep. Sp. Nov. 12: 346. 1913. – Cyclosorus cylindrothrix (Rosenst.) Ching, Bull. Fan Mem. Inst. Biol. 8: 199. 1938; Holttum, Dansk Bot. Ark. 20: 22. 1961; Boonkerd & Pollawatn, Pterid. Thailand: 223. 2000. – Cyclosorus parasiticus var. cylindrothrix (Rosenst.) Tardieu & C.Chr., Fl. Indo-Chine 7(2): 382. 1941. – Thelypteris cylindrothrix (Rosenst.) K.Iwats. in Hara, Fl. E. Himal.: 482. 1966; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 64. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 423. 1988. – Christella cylindrothrix (Rosenst.) Holttum in B.K.Nayar & S.Kaur, Companion Handb. Ferns Brit. India: 208. 1974; Holttum, Kew Bull. 31: 308. 1976.

Dryopteris procurrens auct. non (Mett.) Kuntze: C.Chr., Contr. U.S. Natl. Herb. 26: 330. 1931.

Description

Rhizome creeping, about 5 mm diam.; scales narrow, up to 7 by 1 mm, brown, hairy. Stipes up to 70 cm long, hairy throughout, scaly and dark at base. Laminae oblong-lanceolate, acute at apex, up to 48 by 28 cm; basal 1 or 2 pairs of pinnae deflexed, not shortened, middle pinnae patent or ascending, more or less falcate, caudate-acuminate at apex, truncate at sessile base, deeply lobed nearly to costa, up to 15.5 by 2.2 cm; rachis and costa rather densely hairy throughout; segments oblong, oblique, moderately acute to rounded at apex, entire, up to 7 by 3 mm; venation pinnate, veinlets simple, up to 18 pairs, the lowest pairs uniting to form excurrent veinlets towards callous-sinus, hairy as well as glandular; texture thinly papyraceous, pale green, densely hairy with setose unicellular hairs, glandular on lower surface; glands orange to red, round to clavate, sessile, rather dense. Sori medial; indusia small, persistent, shortly hairy .

Distribution in Thailand

NORTHERN: Chiang Mai, Chiang Rai, Lamphun, Lampang, Tak; NORTH-EASTERN: Loei.

Wider Distribution

E Himalaya and SW China.

Ecology

On rather dry ground in deciduous or mixed forests at medium elevation, 500–1000 m alt., locally abundant.

Proposed IUCN Conservation Assessment

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

Voucher specimens - Thailand

Koyama & Phengklai T-39590, Lampang (QBG).