Family

Pteridaceae, subfamily Cheilanthoideae

Nomenclature

Cheilanthes delicatula Tagawa & K.Iwats., Acta Phytotax. Geobot. 25: 19. 1971; Tagawa & K.Iwats., Fl. Thailand 3: 205. 1985; Boonkerd & Pollawatn, Pterid. Thailand: 120. 2000.

Description

Rhizome short creeping, bearing close fronds, densely scaly; scales linear, up to 3 by 0.1 mm, bright brown. Stipes slender, about 0.2 mm in diameter, bright castaneous, polished, glabrous or rarely scaly with small hair-like scales 1.5–2.5 mm long. Laminae oblong-subdeltoid, widest at base, acute at apex, about 2.5 by 1.5 cm, bipinnatifid; rachis castaneous, grooved on upper surface, raised below, glabrous, narrowly winged nearly to the base; pinnae patent or upper ascending, opposite, adnate or decurrent at base, oblong to oblong-subdeltoid, round at apex, up to 10 by 5 mm, pinnatifid to pinnatisect; segments with one to four veinlets, lobes one-nerved, thin and glabrous; veins distinct on both surfaces with darker colour. Sori at apex of veinlets, with one to four sporangia; indusial flaps moderately acute to acuminate at apex , up to 0.7 by 0.5 mm, pale.

Distribution in Thailand

NORTHERN: Chiang Mai.

Wider Distribution

Endemic to Thailand.

Ecology

Without record of habitat; probably in crevices of rocks.

Proposed IUCN Conservation Assessment

Data Deficient (DD). For a long time this species was only known from the type collection from of Doi Inthanon.  It has since been rediscovered in Nan Province but its population size and wider distribution are uncertain.  More research is needed.

Notes

Cheilanthes is a difficult genus that needs more taxonomic research.