Family

Cyatheaceae

Nomenclature

Cyathea gigantea (Wall. ex Hook.) Holttum, Gard. Bull. Straits Settlem. 8: 318. 1935; Rev. Fl. Malaya ed. 1, 2: 128, f. 53. 1955 [‘1954’]; Holttum, Dansk Bot. Ark. 20: 18. 1961; Holttum, Fl. Males., Ser. II, Pterid. 1: 124. 1963; Holttum, Kew Bull. 19: 476. 1965; Tagawa & K.Iwats., SouthE. Asian Stud. 3(3): 74. 1965; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 46. 197; Tagawa & K.Iwats., Fl. Thailand 3: 105. 1979; Boonkerd & Pollawatn, Pterid. Thailand: 113. 2000. – Alsophila gigantea Wall ex Hook., Sp. Fil. 1: 53. 1844; R.M.Tryon, Contr. Gray Herb. 200: 32. 1970; Newman et al., Checkl. Vasc. Pl. Lao PDR: 25. 2007.

Alsophila glabra auct. non (Blume) Hook.: Newman et al., Checkl. Vasc. Pl. Lao PDR: 25. 2007. – Cyathea glabra auct. non  (Blume) Copel.: Tardieu & C.Chr., Fl. Indo-Chine 7(2): 83. 1939.

Description

Trunks up to 2 m or more tall. Stipes up to 50 cm or more long, nearly black or deep castaneous, polished, densely covered with spreading scales; scales up to 1.5 cm long, 2 mm broad, dark brown to nearly black, shining, stiff, edges pale, thinner, ragged and eroding with age, rather broad, pale; pneumathodes small, in a single row, distinct; main rachis castaneous to nearly black, minutely scaly, smooth; pinnae up to 70 cm or more long, 25 cm wide, acuminate at apex; pinna-rachis hairy on upper surface, sparsely warty or scaly beneath, dark at base, paler towards apex; pinnules about 2.5 cm apart, patent or ascending, straight or slightly falcate lanceolate, caudate-acuminate at apex, cordate at base, very shortly stalked, up to 12 cm long, 2 cm wide, lobed to more than 1/3 way towards costae; lobes round subdeltoid, round at apex, oblique, falcate, serrate at margin, up to 4 mm broad, with narrow sinus; texture thin, papyraceous, green, veins pinnate, veinlets simple, all free. Sori close to costule or medial, exindusiate .

Distribution in Thailand

NORTHERN: Chiang Mai, Chiang Rai, Tak; NORTH-EASTERN: Loei; SOUTH-WESTERN: Kanchanaburi; SOUTH-EASTERN: Chanthaburi, Trat; PENINSULAR: Ranong, Surat Thani, Phangnga, Nakhon Si Thammarat, Trang, Satun, Yala.

Distribution in Laos

Attapeu, Hua Phan, Xieng Khouang.

Distribution in Cambodia

Kampot

Wider Distribution

E Himalaya, S India, Sri Lanka, Burma, S China, Indochina, Peninsular Malaysia, Sumatra and W Java.

Ecology

On mountain slopes usually in dense tropical evergreen forest, lowland and in lower montane forest to about 1300 m alt.

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. 4747 & 4756, Kanchanaburi, Khao Laem National Park (E); Middleton et al. 4683, Chanthaburi, Khlong Khrue Wai Wildlife Sanctuary (E).