Volume 3 > Part 2 > Year 1989 > Page 213 > Parkeriaceae > Adiantum

6. Adiantum erylliae Tardieu & C.Chr.wfo-0000147065

Notul. Syst. (Paris) 6: 172. f. 1–2. 1938; Tardieu & C.Chr. in Fl. Gen. Indo-Chine 7(2): 184. 1940; Tagawa & K.Iwats., S.E. Asian Stud. 5: 110. 1967. Fig. 16.1.

Accepted Name : This is currently accepted.

Description : Rhizome short, erect, rather densely covered with scales; scales linear, 3–4 mm long, indistinctly bicoloured with black centre and blackish-brown edge. Stipe bright brown to nearly black, 2–8 cm long, glabrous except for scaly basal portion, scales like those on rhizome but concolorous dark brown. Lamina simply pinnate, lanceolate to linear-lanceolate, gradually narrowing upwards, up to 15 by 3 cm; rachis glabrous throughout, often prolonged and rooting at tip; lateral pinnae distinctly stalked, stalks slender, 1.5–4 mm long; leaflets fan-shaped, up to 1.3 by 1.8 cm, basal two edges entire, straight or round, forming less than right angle, distal margin round, subentire, or lobed to the depth of ⅕ of length of leaflets, middle sinus sometimes deep to midway, sinus narrow or a little wider, lobes round and subentire, papyraceous, glabrous; veins dichotomous, dense, a little raised. Sori round or a little wider, up to ten for each leaflets close to each other; pseudo-indusia 1.5–2 mm broad, up to 3 mm long.

Thailand : NORTHERN: Chiang Mai (Mae Klang), Lampang, Tak (type); SOUTH-WESTERN: Kanchanaburi (Sai Yok); PENINSULAR: Surat Thani (Ko Pha-ngan), Phangnga (Khao Katha Khwam, Khao Toei), Krabi (Ao Luek).

Distribution : Tonkin, Cambodia.

Ecology : On dry slopes or in crevices of limestone caves in light shade at low altitudes.

Notes: This is a distinct species of the Adiantum philippense group, and has affinity also to A. capillus-junoris in China. The form of leaflets, which is the most important key character, is somewhat variable: Khao Katha Khwam plant is a smaller plant with leaflets up to 8 mm long and wide; Khao Toei plant is thin in texture and the distal end of leaflets being round, and is probably a specimen of young plant; Sai Yok plant is again different in its leaflets which are orbicular-subdeltoid in outline and are up to 2.2 cm long and wide; it is more like A. capillus-junoris, but different in deep cleft round sori that are at most 3 mm long.

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