Family

Cyatheaceae

Nomenclature

Cyathea contaminans (Wall. ex Hook.) Copel., Philipp. J. Sci. 4: 60. 1909; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 86. 1939; Holttum, Rev. Fl. Malaya ed. 1, 2: 119. 1955 [‘1954’]; Holttum, Fl. Males., Ser. II, Pterid. 1: 135. 1963; Holttum, Kew Bull. 19: 485. 1965; Tagawa & K.Iwats., SouthE. Asian Stud. 3(3): 74. 1965; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 46. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 106. 1979; Boonkerd & Pollawatn, Pterid. Thailand: 45, 113. 2000; Newman et al., Checkl. Vasc. Pl. Lao PDR: 26. 2007. – Alsophila contaminans Wall. ex Hook., Sp. Fil. 1: 52, t. 18B. 1844.

Chonophora glauca Blume, Enum. Pl. Javae.: 243 1828, non Cyathea glauca Bory 1804. – Alsophila glauca (Blume) J.Sm., J. Bot. 3: 419. 1841; Bedd., Handb. Ferns Brit. India: 12 1883, p.p. – Sphaeropteris glauca (Blume) R.M.Tryon, Contr. Gray Herb. 200: 21. 1970.

Description

Trunks up to 10 m or more tall. Stipes up to 60 cm or more long, stout, strongly thorny, purplish, glaucous, scaly near base; scales light brown to paler, to 4 cm long, 3 mm broad, thin, bearing short darker setae at margin; main rachis spiny, glaucous or brown, glabrescent; pinnae up to 80 cm or more long, 30 cm wide, lower ones lightly reduced in size; pinna-rachis light brown or paler, spiny beneath, glabrescent or hairy on upper surface; pinnules about 2.5 cm apart, lanceolate acuminate at apex, subtruncate at base, sessile, patent, almost straight, up to 15 cm long, 2.5 cm wide, deeply lobed almost to costa, a few lowest segments quite free; segments oblique, falcate, round to moderately acute at apex, up to 1.5 cm long, 4.5 mm broad, 5–6 mm apart, crenate at margin; costae and costules glabrous or very sparsely hairy near apices of pinnules, scales rarely residual, small, pale, not bullate; papyraceous, green, glaucous beneath, veins forked, distinct beneath. Sori nearer to costule than to edges of lobes, exindusiate; receptacles large, prominent .

Distribution in Thailand

NORTH-EASTERN: Loei; SOUTH-WESTERN: Phetchaburi; SOUTH-EASTERN: Trat; PENINSULAR: Phangnga, Nakhon Si Thammarat, Trang, Satun.

Distribution in Laos

Khammouane, Xieng Khouang.

Wider Distribution

N India and Malesia.

Ecology

On mountain slopes or stream banks in dense tropical eyergreen forest or in open areas at low altitudes.

Proposed IUCN Conservation Assessment

Least Concern (LC). Although Cyathea species are often exploited for the horticultural industry (mainly for their trunks as a base for epiphytic orchids) this species is widespread and not noticeably being adversely impacted.  Monitoring is necessary.

Notes

Fibrous trunk used for orchid media.

Voucher specimens - Thailand

Middleton et al. 5124, Loei, Phu Suan Sai National Park (E); Middleton et al. 4787, Phetchaburi, Kaeng Krachan National Park (E); Middleton et al. 4639, Trat, Namtok Khlong Kaeo National Park (E).