Polystichum tenggerense Rosenst.
Polystichum tenggerense Rosenst., Repert. Spec. Nov. Regni Veg. 8: 164. 1910; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 95. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 338, f. 29.8 & 29.9. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 209. 2000.
Rhizome massive, erect; scales oblong-ovate, up to 2.5 by 1.2 cm, bicoloured, central portion dark castaneous to nearly black, thin but stiff, margins brown, ferrugineous. Stipes to 60 cm long, brown, grooved above, densely scaly throughout, scales of two kinds, larger ones oblong-ovate, narrow ones up to 1.2 mm in breadth, ferrugineous. Laminae tripinnate to tripinnatifid, oblong-lanceolate, hardly narrowing at base, gradually narrowing towards acute apex, 65–75 by 25–36 cm; rachis densely scaly, larger scales concolorously brown, up to 10 by 5 mm, linear ones ferrugineous, in upper part like downy hairs; pinnae up to 30 or more pairs, the lowest ones subopposite, a little deflexed, middle ones patent, slightly falcate, linear-lanceolate, subtruncate and sessile, attenuate at apex, up to 18.5 by 4.5 cm; pinnules patent, up to 30 pairs, oblong, moderately acute at apex, slightly auricled at acroscopic and dimidiate at basiscopic bases, up to 12 by 5 mm, lobed to half-way; lobes subdeltoid, acuminate at apex, about 1 mm long, up to 1.5 mm broad, apex ending in awns; veins pinnate, softly coriaceous, light green. Sori arranged in one row close to midrib of pinnules or medial between midrib and margin, confluent at maturity; indusia peltate, pale to deep brown, thin, fugacious, glabrous .
Distribution in Thailand
NORTHERN: Chiang Mai.
Sumatra and Java.
In Thailand known only on Doi Inthanon, on humus-rich mountain slopes in dense mossy forest at about 2200 m alt.
Proposed IUCN Conservation Assessment
Least Concern (LC). This species is widespread and not under any known threat.
Voucher specimens - Thailand
Middleton et al. 4907, Chiang Mai, Doi Inthanon National Park (E).
Scales on stipe
Lower surface of lamina with sori
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