Family

Athyriaceae

Nomenclature

Athyrium dissitifolium (Baker) C.Chr., Contr. U.S. Natl. Herb. 26: 296, 332, pl. 18. 1931; Tagawa & K.Iwats., SouthE. Asian Stud. 3(3): 87. 1965; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 101. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 446, f. 48.1. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 152, 153, 189. 2000. – Polypodium dissitifolium Baker, Bull. Misc. Inform. Kew 1895: 54. 1895. Type: Henry 13078B, Yunnan, China (E).

Description

Terrestrial. Rhizome short creeping, bearing close fronds; scales narrow, up to 10 by 1 mm, pale brown, entire. Stipes up to 30 cm long, stramineous, dark brown at broadened base, scaly in lower part. Laminae narrow, widest at base, acuminate to attenuate at apex, up to 30 by 12 cm in soriferous and 15 cm wide in sterile fronds, bipinnatifid; pinnae more than 15 pairs, lower pinnae shortly stalked, linear-lanceolate, falcate, truncate at base, acuminate at apex, up to 6 by 1.5 cm in soriferous and up to 8 by 2.2 cm in sterile ones, deeply lobed nearly to costa, upper pinnae becoming smaller upwards; ultimate segments patent to oblique, oblong to subdeltoid, rounded to moderately acute at apex, toothed at margin; papyraceous to subcoriaceous, light green; veins pinnate, veinlets simple or forked, ending in sharp teeth at margin. Sori oblong or sometimes round , naked, sometimes uniting with the next ones at maturity.

Distribution in Thailand

NORTHERN: Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun.

Wider Distribution

E Himalaya and Yunnan.

Ecology

On rather dry ground or on mountain slopes in mixed or evergreen forests at 600– 1500 m alt.

Proposed IUCN Conservation Assessment

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

Voucher specimens - Thailand

Middleton et al. 5014, Chiang Mai, Doi Chiang Dao Wildlife Sanctuary (E).