Drynaria roosii Nakaike


Named after Marco C. Roos (1955 - present), a Dutch botanist.




Drynaria roosii Nakaike, New Fl. Jap. Pterid.: 841. 1992. – Drynaria fortunei (Kunze ex Mett.) J.Sm. in Seem., Bot. Voy. Herald: 425. 1857, non T.Moore; Bedd., Suppl. Ferns Brit. Ind.: 92: 1892; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 518. 1941; Tagawa, J. Jap. Bot. 38: 329. 1963; Tagawa & K.Iwats., Fl. Thailand 3: 546, f. 55.1. 1989; Boonkerd & Pollawatn, Pterid. Thailand: 269. 2000; Dy Phon, Dictionary of Plants used in Cambodia: 251. 2000; Newman et al., Checkl. Vasc. Pl. Lao PDR: 29. 2007. – Polypodium fortunei Kunze ex Mett., Abh. Senck. Naturf. Ges. 2: 121, t. 3, f. 42–45. 1857.


Rhizome creeping, up to 1.2 cm diam., densely scaly throughout; scales, narrow, gradually narrowing from peltate base towards attenuately tailed apex, up to 8 by about 1.4 mm, dark brown with paler margin, distinctly toothed at margin. Nest-leaves sessile, adnate, oval, up to 10 by 6.5 cm, lobed to a half-way between midrib and margin; lobes oblong-subdeltoid, acuminate at apex, entire, up to 1.5 cm broad. Foliage-leaves: stipes short, up to 10 cm long, narrowly winged throughout; laminae narrowly oblong, slightly narrowing from base to apex, up to 40 by 25 cm; lobed nearly to rachis, remaining narrow wings of rachis less than 5 mm in breadth, narrowly oblong from base towards moderately acute apex, entire but irregularly waved, up to 11 by 2.5 cm, the basal lobes the longest or reduced; costa and main veins minutely pubescent, main veins and cross veins distinct on both surfaces the other veins less so, anastomosing with free included veinlets; chartaceous, glabrous. Sori dispersed from the upper central portion downwards, two rows of round sori or a single row of crescent sori between adjacent main veins.

Distribution in Thailand

NORTHERN: Chiang Mai.

Distribution in Laos

Xieng Khouang.

Wider Distribution

S China, Indochina and Taiwan.


On the trunks of trees.

Proposed IUCN Conservation Assessment

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


Said to have various medicinal uses (Dy Phon, 2000).

Site hosted by the Royal Botanic Garden Edinburgh. Content managed by Stuart Lindsay, Gardens by the Bay, Singapore and David Middleton, Singapore Botanic Gardens. Last updated 24 January 2012