Arthromeris phuluangensis Tagawa & K.Iwats.

Family

Polypodiaceae

Nomenclature

Arthromeris phuluangensis Tagawa & K.Iwats., Acta Phytotax. Geobot. 22: 100. f. 4. 1967; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 61. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 565. 1989; Boonkerd & Pollawatn, Pterid. Thailand: 263. 2000. – Type: Tagawa et al. T-1488, Thailand, Loei, Phu Luang (holotype KYO; isotype P).

Description

Epiphytic or lithophytic. Rhizome long creeping, about 6 mm diam., densely covered with scales; scales pseudopeltate, subulate, up to 17 mm long including the long tapering filiform portion 7 to 10 mm in length, about 2 mm broad, with tiny teeth or hairs along margin, whitish with brownish centre. Stipes 16–25 cm long, glabrous, stramineous or pale brown. Laminae ovate-oblong in outline, 35–60 by 30–32 cm; rachis like the upper part of stipes; lateral pinnae 7–12 pairs, subopposite, the basal two or three pairs the largest, patent and straight or slightly undulate on the margin, margined with cartilaginous membrane, deeply cordate at sessile base, long-acuminate and caudately prolonged at apex, up to 25 by 3 cm, the upper ones smaller, usually up to 15 by 1.5 cm; terminal pinna like the middle lateral ones, sometimes slightly auricled at base, up to 18 by 2 cm; costae distinct on both surfaces, lateral main veins more than 45 pairs in larger pinnae, visible on both surfaces; thinly papyraceous. Sori on veins or terminal on included veinlets, in two rows between adjacent main veins, round, in several rows on each side of costae, up to 1 mm diam., superficial .

Distribution in Thailand

NORTHERN: Phitsanulok; NORTH-EASTERN: Loei.

Wider Distribution

Endemic to Thailand.

Ecology

On mossy tree trunks or on mossy rocks in dense evergreen forests at ridge at 1500–1600 m alt.

Similar species

Arthromeris lehmannii (Mett.) Ching

Proposed IUCN Conservation Assessment

Least Concern (LC). Although this species is known only from Phu Miang and Phu Luang and has an extent of occurrence of less than 5000 km2 it occurs in two protected areas with no current great levels of disturbance.

Voucher specimens - Thailand

Tagawa et al. T-1488, Loei, Phu Luang (P); Shimizu et al. T-11438, Phitsanulok, Phu Rom Rot of Phu Miang (P).

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