Hymenophyllum javanicum Spreng.

Family

Hymenophyllaceae

Nomenclature

Hymenophyllum javanicum Spreng., Syst. Veg. 4: 132. 1827; Bedd., Handb. Ferns Brit. India: 32. 1883; Copel., Philipp. J. Sci. 64: 120, pl. 59. 1937; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 54. 1939; Holttum, Rev. Fl. Malaya ed. 1, 2: 83, f. 24. 1955 [‘1954’]; Tagawa & K.Iwats., Fl. Thailand 3: 611. 1989; Boonkerd & Pollawatn, Pterid. Thailand: 74. 2000. – Mecodium javanicum (Spreng.) Copel., Philipp. J. Sci. 67: 20. 1938; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 38. 1967; Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 51. 1968; Tagawa & K.Iwats., Fl. Thailand 3: 71. 1979.

Description

Rhizome laxly branched, about 0.5 mm diam. Stipes remote, naked but the very base hairy, 2–5 cm long, winged except for the basal portion with undulate or crisped wings. Laminae oblong-subdeltoid, acute to moderately acute at apex, tripinnate to quadripinnatifid, glabrous, 4–7(–8.5) cm long, to 5 cm wide at the widest basal portion; pinnae 5 or more in pairs, the basal ones to 3 cm long, 2 cm wide, oblong-subdeltoid, moderately acute to round at apex, broadly cuneate to round at base, stalked, the upper ones gradually smaller upwards, oblong in outline; ultimate segments narrow, round to obtuse at apex, entire but undulate or crisped at margin, 0.6–1 mm broad, to 4 mm long, decurrent onto every axis forming distinct, waved or crisped wings of 0.8 mm or so. Sori scattered usually on the apical parts of pinnae; involucre subdeltoid to oblong, 1.2–1.6 mm long, to 1 mm broad, the lips finely toothed, receptacles clavate to filiform, wholly included in the involucre . Cell walls thin, straight.

Distribution in Thailand

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

Wider Distribution

Throughout the tropics of Asia and Oceania.

Ecology

On mossy tree trunks in dense tropical evergreen forest, rather common at medium or higher altitudes.

Proposed IUCN Conservation Assessment

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

Voucher specimens - Thailand

Williams et al. 1884, Krabi (E).

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