Family

Pteridaceae, subfamily Pteridoideae

Nomenclature

Pteris longipinnula Wall. ex J.Agardh, Recens. Spec. Pter.: 19. 1839; Bedd., Handb. Ferns Brit. India: 112. 1883; Holttum, Rev. Fl. Malaya ed. 1, 2: 404. 1955 [‘1954’]; Tagawa & K.Iwats., Fl. Thailand 3: 239. 1985; Boonkerd & Pollawatn, Pterid. Thailand: 129. 2000.

Description

Rhizome short, suberect, scaly; scales narrowly elliptic, distinctly bicoloured, the central portion dark brown, stiff, up to 3 by 0.4 mm, marginal portion pale brown, thin, composed of quadrangular cells and decaying from margin, 0.1 mm broad on each side. Stipes stramineous, slightly castaneous to purplish near base, 60–80(–110) cm long, slightly grooved above and terete below, glabrous. Laminae oblong-ovate to ovate, acute at apex, about 45(–82) by 30(–60) cm, bipinnatisect; rachis hairy in grooves; lateral pinnae 3–4 pairs, all nearly equal in size and form, ascending, with short stalks 3–10 mm long, elliptic or narrowly so, round to broadly cuneate at base, the base decurrent to stalks, caudate at apex with apical segments up to 30 by 5 mm, up to 22(–35) by 8.7 cm at middle portions; costa green, stramineous in dried specimens, grooved, bearing slender spines; ultimate segments 20–25 pairs, narrowly elliptic, falcate, rounded at apex, up to 57 by 12 mm, the lower basal ones usually longer than upper ones, edges entire or undulate, thickened; veins simple or more commonly forked, basal posterior ones springing directly from costa. Sori linear, along margin of ultimate segments; indusia up to 0.7 mm broad, thin but firm, entire .

Distribution in Thailand

SOUTH-WESTERN: Phetchaburi; PENINSULAR: Chumphon, Surat Thani, Nakhon Si Thammarat, Yala.

Wider Distribution

S India, Malesia. The circumscription and the range of this species are as yet not certain.

Ecology

Terrestrial near marshes at low altitudes.

Proposed IUCN Conservation Assessment

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

Voucher specimens - Thailand

Middleton et al. 4793, Phetchaburi, Kaeng Krachan National Park (E).