Volume 3 > Part 3 > Year 1988 > Page 336 > Dryopteridaceae > Polystichum

3. Polystichum eximium (Kuhn) C.Chr.

Index Filic. Suppl. III: 163. 1934; Tagawa & K.Iwats., S.E. Asian Stud. 5: 94. 1967, p.p.— Phegopteris eximia Mett. ex Kuhn, Linnaea 36: 107. 1869.

Accepted Name : Polystichum anomalum (Hook. & Arn.) J.Sm.
Ferns Brit. For.: 151. 1866.

Synonyms & Citations :

Description : Rhizome short, ascending; scales oblong-subdeltoid, acuminate to tailed at apex, up to 20 by 4 mm, entire, bicoloured, central portion shining black, rigid and tough, margin brown, thinner. Stipe stramineous, 25–60 cm long, scaly throughout; scales at base very dense, consisting of two kinds, one like those on rhizome, the other linear, concolorous, brown, serrate at margin, scales on upper part of stipe linear, up to 1 cm long, at most 0.5 mm broad, black or dark brown. Lamina oblong-lanceolate, widest at middle, 35–50 by about 25 cm; rachis gemmiferous, scaly throughout; pinnae more than 15 pairs, patent or slightly ascending, lower ones lanceolate, broadly cuneate at base, acuminate at apex, more or less falcate, 10–13 by 3–3.5 cm, shortly stalked; pinna-rachis scaly underneath, grooved on upper surface; pinnules close to imbricate, oblong or narrowing from base to apex, falcate, acute at apex, slightly auricled at acroscopic and dimidiate at basiscopic bases, 15–25 by 7–10 mm; veins a little raised on lower surface; coriaceous, green, glabrous on laminar surface. Sori submarginal or scattered on lower surface of pinnules; indusia about 1.2 mm diam., persistent.

Thailand : NORTHERN: Chiang Rai, Chiang Mai (Chiang Dao, Huai Mae Pan, Doi Suthep, Khun Kong Sang); NORHT-EASTERN: Loei (Phu Luang, Phu Kradueng).

Distribution : According to the current definition of this species : tropical Asia from Sri Lanka (type) northwards to southern edge of Japan.

Ecology : On mountain slopes in dense evergreen forests at 700–1,200 m alt.

Notes: the typification of this species is rather difficult and we are not sure at present about the correct name of the Thai plants. The Ceylon Plants are not gemmiferous; we are uncertain also about the identity of the Thai plants with Polystichum indochinensis Tardieu & C.Chr. of Indochina, P. fibrillosum Ching of China and P. gemmiferum Tagawa of Japan.

E-version notes : For more details see Ferns of Thailand, Laos and Cambodia.