Cornopteris opaca (D.Don) Tagawa
Cornopteris opaca (D.Don) Tagawa, Acta Phytotax. Geobot. 8: 92. 1939; Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 176. 1969; M.Kato, Acta Phytotax. Geobot. 30: 108. 1979; Tagawa & K.Iwats., Fl. Thailand 3: 441, f. 46.10–11. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 190. 2000. – Hemionitis opaca D.Don, Prodr. Fl. Nepal.: 13. 1825. – Diplazium opacum (D.Don) Christ, Bull. Acad. Int. Geogr. Bot. 1906: 242. Tardieu & C.Chr., Fl. Indo-Chine 7(2): 261. 1940.
Rhizome thick, ascending to suberect, bearing a few fronds near apex; roots fleshy and green; scales narrow, up to 8 by 2 mm, entire, brown, membranous, not clathrate. Stipes up to 30 cm or more long, stramineous to brown, more or less broadened at scaly base. Laminae bipinnate to tripinnatifid, oblong with acute apex and round base, about 50 by 25 cm; pinnae 9–11 pairs, subopposite, ascending, subsessile or shortly stalked in larger ones; rachis grooved, the grooves decurrent to those of pinnae, cluster of small outgrowths at junction of rachis and costae, sometimes also at junction of costae and costules, these outgrowths sometimes with a linear orange-brown scale at apex; pinnules of the larger pinnae narrowly oblong-subdeltoid, acute to acuminate at apex, truncate or broadly cuneate at sessile base, about 8 by 2.4 cm, lobed nearly to costule with subquadrangular lobes with obtuse apex and subentire or crenate margin of about 1 by 0.5 cm, pinnules of the upper pinnae like the lobes of larger pinnules; herbaceous to thin-papyraceous, usually blackish when dry; veins pinnate with simple or rarely forked veinlets reaching or almost reaching the very margin of lobes. Sori dorsal on veins, oblong or V-shaped, exindusiate, sporangia not setiferous.
Distribution in Thailand
NORTHERN: Mae Hong Son, Chiang Mai, Lampang; SOUTH-WESTERN: Phetchaburi.
N India, Nepal to SW Japan, south to Vietnam; also in Java.
Terrestrial on mountain slopes at about 1000 m alt. or in shaded wet alluvial area.
Proposed IUCN Conservation Assessment
Least Concern (LC). This species is widespread and not under any immediate known threat.
Voucher specimens - Thailand
Maxwell 91-222, Mae Hong Son, Ban Mae Sawan Noi (P); Maxwell 91-250, Chiang Mai, Mae Soi (E); Middleton et al. 4792, Phetchaburi, Kaeng Krachan National Park (E).
Rhizome and crozier
Upper surface of pinnae
Spines on costa and costules
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