Dryopteris porosa Ching




Dryopteris porosa Ching, Bull. Fan Mem. Inst. Biol. 8: 460. 1938; Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 114, f. 10. 1968; Tagawa & K.Iwats., Fl. Thailand 3: 350, f. 32.1 & 32.2. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 204. 2000.


Rhizome short, massive. Stipes stramineous, up to 1 cm at base, about 50 cm long, densely scaly at base, sparsely clad with small scales or glabrescent upwards, grooved above; scales thin but firm, about 25 by 5 mm, brown, entire. Laminae oblong-subdeltoid, acute at apex, 60 by 50 cm, tripinnate; rachis very sparsely and minutely scaly, grooved above; pinnae about 10 pairs, patent or ascending, basal pinna the largest, oblong-subtriangular, up to 40 by 1.5 cm; pinna-rachis narrowly winged in slender portion, grooves decurrent into those of rachis; segments oblong, oblique, 15 by 5 mm, rounded and serrate, cuneate and sessile or adnate at base, lobed to halfway, lobes round-subtriangular, acuminate or acute at apex, up to 3 mm long and wide; chartaceous, light green on upper surface, midrib and veins impressed above, distinct beneath, veins ending in large globose hydathodes within the margin of lobes; paler beneath, lower midrib surface with numerous large stomata, margin cartilaginous. Sori dorsal on veinlets, large, costular or medial; indusia large, round-reniform, about 1.7 mm diam., persistent .

Distribution in Thailand

NORTHERN: Phitsanulok.

Wider Distribution

China (Guizhou and Sichuan).


On humus-rich floor of dense evergreen forests at about 1600 m alt.

Proposed IUCN Conservation Assessment

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


Only once collected: Tagawa et al. T-1 1593 (KYO).

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