Arachniodes assamica (Kuhn) Ohwi

Family

Dryopteridaceae

Nomenclature

Arachniodes assamica (Kuhn) Ohwi, J. Jap. Bot. 37: 36. 1962; Tagawa & K.Iwats., Acta Phytotax. Geobot. 24: 62. 1969; Tagawa & K.Iwats., Fl. Thailand 3: 344. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 198. 2000. – Aspidium assamicum Kuhn, Linnaea 36: 108. 1869. – Rumohra assamica (Kuhn) Ching, Sinensia 5: 47, pl. 4–6. 1934; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 322. 1941.

Lastrea affinis Bedd., Handb. Ferns Brit. India: 230. 1883, p.p.

Description

Terrestrial. Rhizome short, creeping or suberect; scales narrowly elliptic, gradually narrowing from base towards hair-pointed apex, up to 10 by 2.5 mm, concolorous brown, entire. Stipes stramineous, about 25 cm long, sparsely scaly. Laminae bipinnate, oblong, acute at apex, round at base, about 35 cm long and wide; rachis bearing linear scales, grooved above; pinnae several pairs, usually the basal ones the largest, stalked with petioles about 5 mm long, narrowly elliptic, round at base, narrowing towards long-acuminate apex, about 17 by 4 cm, upper pinnae gradually becoming smaller upwards, more ascending; pinnules rhomboid, acute, slightly auricled at subtruncate acroscopic base, narrowly cuneate at basiscopic base, crenate at margin, up to 3 by 1 cm, distal ones adnate at base, decurrent into narrow wings of scaly costa; coriaceous; veins visible on under surface, minutely scaly beneath with fimbriate scales. Sori terminal on veinlets, in one or two irregular rows at each side of midrib, round; indusia up to 0.7 mm diam., usually ferrugineous at maturity, glabrous .

Distribution in Thailand

NORTHERN: Chiang Mai.

Wider Distribution

N India, Burma, SW China, N Vietnam, and Japan.

Ecology

In lower montane forest along streamlets at high altitudes at about 2200 m.

Proposed IUCN Conservation Assessment

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

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