Diplazium dilatatum Blume




Diplazium dilatatum Blume, Enum. Pl. Javae: 194. 1828; Holttum, Gard. Bull. Straits Settlem. 11: 85. 1940; Sledge, Bull. Brit. Mus. (Nat. Hist.) Bot. 2: 303. 1962; Tagawa & K.Iwats., SouthE. Asian Stud. 3(3): 87. 1965; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 106. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 464. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 191. 2000. – Athyrium dilatatum (Blume) Milde, Bot. Zeit. 1870: 353. 1870; Holttum, Rev. Fl. Malaya ed. 1, 2: 574, f. 341. 1955 [‘1954’].

Asplenium bellum C.B.Clarke, Trans. Linn. Soc. London, Bot. 1: 496, t. 63, f. 2. 1880. – Asplenium umbrosum var. bellum (C.B.Clarke) Hosseus, Beih. Bot. Centralbl. 28(2): 364. 1911.

Asplenium maximum D.Don, Prodr. Fl. Nepal. 8: 1825. – Diplazium maximum (D.Don) C.Chr., Index Filic.: 235. 1905; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 263. 1940.


Rhizome massive, erect; scales to about 20 by 2 mm, more commonly narrower, dark brown, black-margined, distinctly toothed. Stipes 40–100 cm or more high, densely scaly near base, dark brown to stramineous. Lamina 65–200 by 40–100 cm, bipinnate to tripinnatifid; pinnae 8–14 pairs, narrowly oblong, acuminate at apex, basal pinnules usually a little reduced, up to 50 by 25 cm; larger pinnule oblong-subtriangular, gradually narrowing towards attenuate apex, basal lobes a little reduced, cordate at stalked base, lobed halfway to costa, up to 13 by 2.5 cm; lobes subdeltoid to semi-orbicular, round to moderately acute at apex, subentire or serrate, up to 7 mm in breadth; veins pinnate with 5–9 pairs of simple or forked veinlets. Sori along veinlets about 5 mm long.

Distribution in Thailand

NORTHERN: Chiang Mai, Chiang Rai, Tak, Phitsanulok; NORTH-EASTERN: Phetchabun, Loei; EASTERN: Chaiyaphum, Nakhon Ratchasima; CENTRAL: Nakhon Nayok; SOUTH-EASTERN: Chanthaburi; PENINSULAR: Surat Thani, Trang.

Distribution in Laos

Xieng Khouang.

Wider Distribution

India, Burma, S China, Taiwan, Ryukyu, S Japan, Indochina, throughout Malesia to N Australia.


On moist or humus-rich mountain slopes in dense gloomy forests at 400–1500 m alt., rather common.

Similar species

Diplazium simplicivenium Holttum

Proposed IUCN Conservation Assessment

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


The Delacour specimen recorded from Nape in Khammouane in Laos by Tardieu & Christensen in Fl. Indo-Chine is a Cyatheasp.

Voucher specimens - Laos

Poilane 2389, Xieng Khouang (P); Poilane 2285, Xieng Khouang (P);

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