Lepisorus oosphaerus (C.Chr.) Ching

Family

Polypodiaceae

Nomenclature

Lepisorus oosphaerus (C.Chr.) Ching, Bull. Fan Mem. Inst. Biol. 4: 70. 1933; Bir & Trikha, Amer. Fern J. 64: 58. 1974; Tagawa & K.Iwats., Fl. Thailand 3: 511. 1989; Boonkerd & Pollawatn, Pterid. Thailand: 274. 2000. – Polypodium oosphaerum C.Chr., Contr. U.S. Natl. Herb. 26: 334, pl. 29. 1931. – Pleopeltis oosphaera (C.Chr.) Tagawa & K.Iwats., Acta Phytotax. Geobot. 22: 100. 1967.

Description

Description from the protologue :
Rhizome long creeping, 6 to 8 mm thick, densely covered with peltate, imbricate, ovate-acute, entire, brown scales, these nearly concolorous, the central cell-walls somewhat darker than the rest, most of the cells rectangular, with straight walls, those bordering the edges smaller, irregular, with flexuose walls. Fronds at distances of 2 to 3 cm, the stipes very short, rarely 1 cm long; laminae simple, entire, broadly lanceolate, to 40 cm long, 5 to 6 cm broad below the middle, then gradually attenuate to the subacute curved apex, less narrowed downward, about 2 cm broad at extreme base, here rotund-truncate; leaf tissue light-green, thinly papyraceous, glabrous, the upper side densely fusco-punctate from the hydathodes of the free veinlets; costa yellowish-brown, raised below and there furnished with a few ovate-lanceolate, deciduous scales; primary lateral veins very fine, but distinct two-thirds of the way to the edge, very oblique, 1.5 to 2 cm apart, the included network of veins very fine but distinctly seen in the dried frond, the areoles with many free veinlets; sori confined to the upper half of the blade, borne in a single row at either side, medial, obliquely elliptic, 6 mm long, 4 mm broad, yellowish brown, without peltate scales, but with numerous paraphyses among the sporangia. Spores monolete .

Distribution in Thailand

NORTHERN: Chiang Mai.

Wider Distribution

Endemic to Thailand.

Ecology

On branches of trees at 1500–1650 m alt.

Proposed IUCN Conservation Assessment

Vunerable VU D2. This species is only known from two sites in Chiang Mai, Doi Sutep and Doi Hua Mot.  Doi Sutep, although a National Park, suffers from a number of disturbances.  Any threats at Doi Hua Mot need to be investigated.

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