Family

Polypodiaceae

Nomenclature

Lepisorus subconfluens Ching, Bull. Fan Mem. Inst. Biol. 4: 85. 1933; Bir & Trikha, Amer. Fern J. 64: 60. 1974; Tagawa & K.Iwats., Fl. Thailand 3: 514, f. 51.2. 1989; Boonkerd & Pollawatn, Pterid. Thailand: 275. 2000. – Pleopeltis subconfluens (Ching) Tagawa & K.Iwats., Acta Phytotax. Geobot. 22: 100. 1967; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 49. 1967.

Polypodium lineare auct. non Thunb.: C.Chr., Contr. U.S. Natl. Herb. 26. 334. 1931.

Description

Rhizome creeping, about 2.5 mm diam., bearing fronds rather closely spaced near apex, scaly; scales oblong-subtriangular with round base and long-attenuate apex, up to 3 by 1 mm, sharply toothed at margin, dark brown to nearly black, the basal marginal portion brown and more or less clathrate. Stipes up to 3 cm long, indistinct from the base of laminae, scaly at base, dark stramineous to nearly black. Laminae linear, up to 30 by 1.2 cm, commonly about 20 by 0.8 cm, attenuate towards both ends; leathery. Sori medial, round to elliptic, about 2.5 mm broad, up to 5 mm long, sometimes fusing to the next ones; the sterile portion of laminae usually revolute, in contrast to the remaining soriferous portion. Spores monolete .

Distribution in Thailand

NORTHERN: Chiang Mai, Chiang Rai, Phitsanulok.

Wider Distribution

Bhutan and SW China (Yunnan).

Ecology

On mossy tree trunks in dense evergreen forests at high altitudes.

Similar species

Lepisorus contortus (Christ) Ching, Lepisorus heterolepis (Rosenst.) Ching.

Proposed IUCN Conservation Assessment

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

Notes

Further taxonomic work is necessary to distinguish Lepisorus contortus (Christ) Ching, Lepisorus heterolepis (Rosenst.) Ching and Lepisorus subconfluens Ching.

Voucher specimens - Thailand

Middleton et al. 4872, Chiang Mai, Doi Suthep (E); Middleton et al 5058, Chiang Mai, Doi Pha Hom Pok National Park (E); Middleton et al. 5098, Phitsanulok, Phu Hin Rong Kla National Park (E).