Family

Dipteridaceae

Nomenclature

Cheiropleuria bicuspis (Blume) C.Presl, Epimel. Bot.:189. 1851 [‘1849’]; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 443, f. 51, 4–5. 1941; Holttum, Rev. Fl. Malaya ed. 1, 2: 136, f. 56. 1955 [‘1954’]; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 47. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 484, f. 49.3–6. 1989; Laferrière, Fl. Males., Ser. II, Ferns and Fern Allies 3: 285, f. 1. 1998; ; Boonkerd & Pollawatn, Pterid. Thailand: 32, 78. 2000. – Polypodium bicuspe Blume, Enum. Pl. Javae: 125. 1828. – Type: Blume s.n., Java (L, sheet 908.328-51)

Description

Rhizome creeping, 6–10 mm diam., densely covered with hairs, bearing fronds 0.3–1.5 cm apart; hairs soft, pale brown, up to 5 mm or more long, multiseptate. Fronds dimorphic. Sterile fronds: stipes up to 30 cm long, hairy at base, glabrous above, stramineous or darker; smaller laminae simple, narrowly bilobed, round at base, entire, up to 15 cm long, 12 cm wide; lobes acuminate with broad rounded sinus between them, up to 8 cm long, entire; main veins several times branching dichotomously, smaller veins forming elaborate network; coriaceous, deep green, paler beneath. Fertile fronds taller; laminae linear-lanceolate, gradually narrowing towards both base and apex, up to 15 cm long, 1.5 cm broad, lower surface wholly covered with sporangia in acrostichoid condition except on main veins and narrow strip at edge, mixed with simple club-shaped hairs.

Distribution in Thailand

NORTH-EASTERN: Loei; PENINSULAR: Nakhon Si Thammarat, Yala.

Wider Distribution

S China, Vietnam, Malesia generally (Sumatra to New Guinea), northwards to the warmer parts of Japan through Taiwan and the Ryukyus.

Ecology

On clayey slope along path in dense forests at higher altitudes (1000–1800 m), rather rare.

Proposed IUCN Conservation Assessment

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