Dryopteris rheophila Mitsuta ex Darnaedi M.Kato & K.Iwats.




Dryopteris rheophila Mitsuta ex Darnaedi, M.Kato & K.Iwats., J. Jap. Bot. 64: 302. 1989; Tagawa & K.Iwats., Fl. Thailand 3: 620. 1989; Boonkerd & Pollawatn, Pterid. Thailand: 205. 2000.


Rhizome erect; rhizome scales persistent, dull brown, ovate, lip to 7 by 4 mm. Stipes 10–40 cm long; laminae oblong-lanceolate to narrowly deltoid-ovate, bipinnate to obscurely tripinnatifid, 17–43 by 7–18 cm; pinnae inserted at angles less than 50° to rachis, middle pinnae oblong, broadest at base, acuminate towards apex, 5–11 by 2–3 cm; pinnules oblong, unequally cuneate at base, obtuse at apex, shallowly lobed, each lobe with a short sharp tooth. Sori medial on acroscopic veinlets, distributed throughout lamina; chromosome number n = 82, 2n 164 (tetraploid</A>); reproduction sexual.

Distribution in Thailand


Wider Distribution

Endemic to Thailand.


On sandstone boulders in streamlet at 1000–1200 m alt.

Similar species

Dryopteris sparsa (D.Don) Kuntze

Proposed IUCN Conservation Assessment

Data Deficient (DD). This species is only known from Phu Kradueng in Loei Province.  The overall distribution of the species there, and the health of the population, requires further research to provide a conservation assessment.


Part of a species complex including Dryopteris sparsa (D.Don) Kuntze, the taxonomy of which requires clarification.

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