Cyathea gigantea (Wall. ex Hook.) Holttum

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).

Young plant

Young plant

Crown

Crown

Base of stipe

Base of stipe

Stipe with pneumathodes

Stipe with pneumathodes

Pinnae

Pinnae

Venation

Venation

Young sori

Young sori

Older sori

Older sori

Older and younger sori

Older and younger sori

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 16 November 2016.