Family

Tectariaceae

Nomenclature

Heterogonium pinnatum (Copel.) Holttum, Sarawak Mus. J. 5: 163. 1949; Holttum, Rev. Fl. Malaya ed. 1, 2: 524, f. 307. 1955 [‘1954’]; Holttum, Kalikasan 4: 229. 1975; Tagawa & K.Iwats., Fl. Thailand 3: 363, f. 33.8. 1988; Holttum, Fl. Males., Ser. II, Pterid. 2: 115. 1991; Boonkerd & Pollawatn, Pterid. Thailand: 206. 2000. – Stenosemia pinnata Copel., Philipp. J. Sci. 1(Suppl. 2): 146. 1906. – Type: Philippines, Mindanao, Zamboanga, San Ramon, 300 ft, 8 Jan 1905, Copeland 1601 (holotype MICH, barcode: MICH1191022, http://quod.lib.umich.edu/h/herb2ic/x-mich1191022/mich1191022.tif).

Description

Description from Holttum, Fl. Males., Ser. II, Pterid. 2: 115. 1991.

Rhizome short, erect. Fronds strongly dimorphic. Sterile frond: stipe dark purplish brown, commonly 15–30 cm long, minutely hairy, later glabrescent on the abaxial surface (persistent longer hairs near apex), basal scales c. 8 mm long, less than 1 mm wide; lamina 15–20(–30) cm long, on young plants deltoid, on older plants elongate; basal pinnae with stalks 2 mm long, above them 1–3 pairs of more or less adnate pinnae often with buds at their bases; basal pinnae to c. 12 x 4 cm, lobed to 5–7 mm from the costa, lobes broad, obtuse, entire; suprabasal pinnae lobed less that half way to costa, upper ones much less deeply; apical lamina deltoid, deeply lobed, lobes entire; veins forming areoles along costae of pinnae; lower surface variably short-hairy on costae, otherwise almost glabrous; upper surface densely hairy on costae with a few short thick hairs near sinuses; bulbils sometimes present on rachis at junction with pinnae. Fertile frond: stipe to at least 45 cm long; lamina to c. 15 cm long, its parts as in sterile fronds but pinnae lobed to a very narrow wing along costae, lobes less that 2 mm wide and well-spaced, covered beneath by sporangia without indusia which project beyond margin .

Distribution in Thailand

PENINSULAR: Surat Thani, Krabi, Nakhon Si Thammarat, Trang, Yala.

Wider Distribution

W Malesia to the Philippines.

Ecology

Terrestrial near streams in jungles at low altitudes.

Similar species

Heterogonium alderwereltii Holttum

Proposed IUCN Conservation Assessment

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

Voucher specimens - Thailand

Middleton et al. 5465, Krabi, Thanbok Khoranee National Park (E); Middleton et al. 5474, Satun, Than Plew Waterfall (E); Middleton et al. 5384, Satun, Ban Rao Pla (E).