Pteridrys australis Ching
Pteridrys australis Ching, Bull. Fan Mem. Inst. Biol. 5: 142, pl. 15, 16, 19(12–13). 1934; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 306. 1941; Holttum, Rev. Fl. Malaya ed. 1, 2: 532, f. 313. 1955 [‘1954’]; Holttum, Dansk Bot. Ark. 20: 31. 1961; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 100. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 390. 1988; Holttum, Fl. Males., Ser. II, Pterid. 2: 7. 1991; Boonkerd & Pollawatn, Pterid. Thailand: 162, 209. 2000. – Type: S.P.Ko 50556, China, Kwangtung Province (PE).
Rhizome short creeping, rather thick, scaly near apex; scales lanceolate, tailed at apex, up to 12 by 1.3 mm, dark-brown, stiff. Stipes stramineous or darker, scaly at base, glabrescent above, 30–50 cm long. Laminae oblong, hardly or a little narrowing at base, pinnate with very deeply lobed pinnae; up to 75 by 40 cm; rachis like the upper part of stipe, hairy throughout; pinnae 20 or more pairs, lanceolate, caudate at apex, broadly cuneate to subtruncate at base, sessile or very shortly stalked, deeply lobed to 3/4 way towards costa, up to 25 by 4 cm; costa and costule raised on both surfaces, hairy beneath; segments oblong to oblong-lanceolate, oblique to falcate, moderately acute at apex, serrate at margin; veins once or twice forked, the basal ones springing from the base of costule; the basal acroscopic branches soriferous, ending at various positions between costule and margin, glabrous. Sori round, a row in medial position at each side of costule; indusia round to elongate reniform, hairy .
Distribution in Thailand
NORTHERN: Chiang Mai, Lampang; SOUTH-EASTERN: Chanthaburi; PENINSULAR: Ranong, Phangnga, Nakhon Si Thammarat, Yala.
Distribution in Laos
S China, Burma, N Vietnam and W Malaysia.
On mountain slopes in dense forests at medium altitudes.
Proposed IUCN Conservation Assessment
Least Concern (LC). This species is widespread and not under any known threat.
Voucher specimens - Thailand
Middleton et al. 4686, Chanthaburi, Khlong Khrue Wai Wildlife Sanctuary (E).
Voucher specimens - Laos
Maxwell 99-220, Vientiane (CMU)
Cross section through rhizome
Upper surface of lamina
Teeth in sinuses on upper frond surface
Lower surface of rachis and lamina
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