Pteridrys cnemidaria (Christ) C.Chr. & Ching




Pteridrys cnemidaria (Christ) C.Chr. & Ching, Bull. Fan Mem. Inst. Biol. 5: 136, pl. 12, 18(8–9), 20(19). 1934; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 304. 1941; Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 116. 1968; Tagawa & K.Iwats., Fl. Thailand 3: 389. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 210. 2000. – Dryopteris cnemidaria Christ, Bull. Acad. Int. Geogr. Bot. 1910: 140.


Rhizome short creeping, thick, scaly near apex; scales brown, linear-lanceolate, up to 20 by 1.3 mm, entire. Stipes up to 80 cm long, stramineous, glabrescent above. Laminae more than 1 m long, up to 70 cm wide, pinnate with deeply lobed pinnae; rachis pale, sparsely appressed-hairy; pinnae more than 20 pairs, long-stalked at base, lanceolate, caudately acuminate, the extreme basal basiscopic pinnules lacking, up to 45 by 10 cm, deeply lobed to 9/10 way towards costa; terminal pinna narrowly oblong-subtriangular, acuminate and tailed at apex, moderately rounded at base, up to 20 by 5 cm; costa raised on both surfaces, sparsely hairy or glabrescent; larger segments lanceolate or narrowly subtriangular, caudately acuminate at apex, serrate at margin, up to 5.5 by 1 cm; papyraceous, deep green, hairy on upper surface; basal veins springing directly from costa, bifurcate or trifurcate, the anterior ones running to the sharp teeth at sinus. Sori round, one or two rows on each side of costule, small, up to 0.7 mm diam.; indusia pale, glabrous .

Distribution in Thailand

NORTHERN: Chiang Mai.

Wider Distribution

Himalayas, SW China, Upper Burma, and S Vietnam.


On moist slopes in dense forests in limestone regions at low altitudes.

Proposed IUCN Conservation Assessment

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

Voucher specimens - Thailand

Maxwell 89-429, Chiang Mai, Doi Chiang Dao (E, L).

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