Family

Athyriaceae

Nomenclature

Diplazium mettenianum (Miq.) C.Chr., Index Filic.: 236. 1906; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 253. 1940; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 103. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 460. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 193. 2000. – Asplenium mettenianum Miq., Ann. Mus. Bot. Lugduno-Batavi 3: 174. 1867.

Description

Rhizome creeping, about 4 mm diam.; scales dark brown to black, narrow, up to 6 by 1 mm, toothed at margin. Stipes up to 50 cm long, green to stramineous with dark basal portion, glabrous. Frond pinnate, oblong with acute apex, about 40 by 25 cm; lower pinnae distinctly stalked, up to 14 by 2.3 cm, attenuately acuminate at apex, round to auricled at acroscopic and round to cuneate at basiscopic bases, lobed to 1/3 way to costa; lobes oblique, rounded to obtuse at apex, subentire to serrate, upper pinnae rather suddenly becoming smaller, adnate and gradually decurrent at base;. thinly chartaceous, deep green when living, brown when dry, paler beneath; veins pinnate, veinlets all simple. Sori on all veinlets, not so long except on basal acroscopic ones, sometimes diplazioid; indusia firm, persistent .

Distribution in Thailand

NORTH-EASTERN: Loei.

Wider Distribution

N Vietnam, China, Taiwan to Japan.

Ecology

On humus-rich slopes in dense forests at about 1100 m alt.

Similar species

Diplazium crenatoserratum (Blume) T.Moore

Diplazium silvaticum (Bory) Sw.

Proposed IUCN Conservation Assessment

Least Concern (LC). This species is widespread outside of Thailand and not under any known threat.

Notes

This is a species of the D. silvaticum group, but distinct in its long creeping rhizome. This is typically a Sino-Japanese species, and Phu Kradueng seems to be, a southernmost locality of this species .