Family

Polypodiaceae

Nomenclature

Lepisorus heterolepis (Rosenst.) Ching, Bull. Fan Mem. Inst. Biol. 4: 86. 1933; Tagawa & K.Iwats., Fl. Thailand 3: 514, f. 51.1. 1989; Boonkerd & Pollawatn, Pterid. Thailand: 273. 2000. – Polypodium lineare var. heterolepis Rosenst., Rep. Sp. Nov. 12: 247. 1913. – Pleopeltis heterolepis (Rosenst.) Tagawa & K.Iwats., Acta Phytotax. Geobot. 22: 100. 1967; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 49. 1967.

Description

Rhizome creeping, about 2.5 mm diam., bearing fronds less than 1 cm apart, densely scaly; scales linear-subtriangular, long-attenuate at apex, toothed at margin, up to 5 by 0.7 mm, central portion with longitudinal, thick-walled cells, marginal portion with more or less clathrate cells, black in colour. Stipes up to 3 cm long, variously winged on upper part, castaneous to stramineous, scaly at base. Laminae linear, long-attenuate at both ends, up to 30 by 1.3 cm; coriaceous; veins invisible, copiously anastomosing. Sori medial, round to elliptic, only on the upper half of frond, sometimes fusing to the next ones in the upper portion. Spores monolete .

Distribution in Thailand

NORTHERN: Chiang Mai, Phitsanulok; NORTH-EASTERN: Loei.

Wider Distribution

Sikkim and SW China (Yunnan).

Ecology

On mossy tree trunks in dense forests at ridge at medium to high altitudes, rather rare.

Similar species

Lepisorus contortus (Christ) Ching, Lepisorus subconfluens 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.