Family

Hymenophyllaceae

Nomenclature

Hymenophyllum badium Hook. & Grev., Icon. Filic.: t. 76. 1828; Copel., Philipp. J. Sci. 64: 144, pl. 76. 1937; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 53. 1939; Holttum, Rev. Fl. Malaya ed. 1, 2: 83, f. 25. 1955 [‘1954’]; Holttum, Dansk Bot. Ark. 20: 16. 1961; Tagawa & K.Iwats., Fl. Thailand 3: 611. 1989; Boonkerd & Pollawatn, Pterid. Thailand: 72. 2000. – Hymenophyllum javanicum var. badium (Hook. & Grev.) Bedd., Handb. Ferns Brit. India: 33. 1883. – Mecodium badium (Hook. & Grev.) Copel., Philipp. J. Sci. 67: 23. 1938; Ching, Fl. Reipubl. Popularis Sin. 2: 137, pl. 10, f. 1–6. 1959; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 38. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 72. 1979.

Description

Rhizome wiry, the rootlets densely hairy, 0.8 mm diam. Stipes hard, naked, up to 1 mm diam., less than 10 cm long, winged except the basal portion, the wings entire, more or less crisped or almost flat, gradually narrowing downwards. Laminae variable to some extent in size and form, usually oblong, occasionally broader or narrower, acute at apex, tripinnate to quadripinnatifid, (5–) 10–13 (–25) cm long, at most 7 cm wide; rachis like the upper part of stipes, winged throughout, wings up to 1.2 mm broad., entire, nearly flat, waved or crisped; pinnae to 10 in pairs, the larger ones oblong to oblong-lanceolate, acute or moderately acute at apex, to 4 cm long, 1.5 cm wide, upper ones gradually smaller; ultimate segments narrowly oblong or somewhat elongate, round to obtuse at apex, entire and flat at margin, 1 mm or broader, the wings of costae and the higher axes not crisped. Sori many on a frond; involucre orbicular-reniform, divided to the very base, 1.5–2.5 mm long, somewhat broader; lips round, entire but occasionally undulate; receptacles capitate, included . Cell walls thin and uniform, rarely a little thicker.

Distribution in Thailand

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

Wider Distribution

N India and S China, southwards throughout Malesia, north to S Japan.

Ecology

On mossy tree trunks or on damp rocks usually in dense tropical evergreen forest, rather common at various altitudes.

Proposed IUCN Conservation Assessment

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

Voucher specimens - Thailand

Middleton et al. 4884, Chiang Mai, Doi Inthanon National Park (E); Middleton et al. 5100, Phitsanulok, Phu Hin Rong Kla National Park (E); Middleton et al. 5147, Loei, Phu Luang Wildlife Sanctuary (E).