Family

Pteridaceae, subfamily Vittarioideae

Nomenclature

Haplopteris angustifolia (Blume) E.H.Crane, Syst. Bot. 22: 514. 1998 [‘1997’]. – Vittaria angustifolia Blume, Enum. Pl. Javae.: 199. 1828; Holttum, Rev. Fl. Malaya ed. 1, 2: 610. 1955 [‘1954’]; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 111. 1967; Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 56. 1968; Tagawa & K.Iwats., Fl. Thailand 3: 225. 1985; Boonkerd & Pollawatn, Pterid. Thailand: 106, 107, 135. 2000.

Vittaria sikkimensis Kuhn, Linnaea 36: 66. 1869; Bedd., Handb. Ferns Brit. India: 406, f. 239. 1883; Ching, Sinensia 1: 180. 1931; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 198. 1940; Holttum, Dansk Bot. Ark. 20: 34. 1961; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 111. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 224, f. 17.5. 1985; Boonkerd & Pollawatn, Pterid. Thailand: 108, 136. 2000. – Haplopteris sikkimensis (Kuhn) E.H.Crane, Syst. Bot. 22: 514. 1998 [‘1997’].

Vittaria ensiformis auct. non Sw.: Tagawa & K.Iwats., SouthE. Asian Stud. 5: 111. 1967.

Description

Rhizome short creeping, 0.7–1.5 mm diam., densely scaly throughout; scales narrow, gradually narrowing from base towards hair-pointed apex, up to 6 by 0.7 mm, brown to greyish-brown, clathrate, minutely toothed at margin. Stipes short or indistinct, green or dark at the very base. Laminae linear to very narrowly elliptic, often slightly broader in upper part, 3–20 cm long, 0.5–3 mm wide, usually curved, acute at apex, gradually narrowing downwards and merging into very narrow wings of stipe, leathery; costa visible on upper surface or indistinct, the margin flat or inrolled, veins anastomosing to form narrow areoles. Sori immersed in deep groove almost at margin of fronds, occupying most of frond  length or limited to the upper half.

Distribution in Thailand

NORTHERN: Chiang Mai, Phitsanulok; NORTH-EASTERN: Phetchabun, Loei; SOUTH-EASTERN: Chanthaburi; PENINSULAR: Nakhon Si Thammarat, Krabi, Trang, Yala.

Distribution in Cambodia

Unspecified.

Wider Distribution

N and NE India, S China, Vietnam, and throughout Malesia east to New Caledonia.

Ecology

On tree trunks, usually on old bark of trees, or on muddy or mossy rocks in dense evergreen forests or montane forest at medium to high altitudes.

Proposed IUCN Conservation Assessment

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

Voucher specimens - Thailand

Middleton et al. 5077, Phitsanulok, Phu Hin Rong Kla National Park (E); Middleton et al. 5150, Loei, Phu Luang Wildlife Sanctuary (E); Williams et al. 1886, Krabi (A, BKF, E); Middleton et al. 3664, Yala, Hala-Bala Wildlife Sanctuary (E).

Voucher specimens - Cambodia

Schnell 10260, Massif de Trois Frontiers (L, P).