Family

Thelypteridaceae

Nomenclature

Cyclosorus lakhimpurensis (Rosenst.) Copel., Gen. Fil. 142. 1947; B.K.Nayar & S.Kaur, Companion Beddome's Handb. Ferns Brit. India 66, 95. 1974. – Dryopteris lakhimpurensis Rosenst., Med. Rijksherb. 31: 7. 1917. – Thelypteris lakhimpurensis (Rosenst.) K.Iwats., Mem. Coll. Sci. Univ. Kyoto B. 31: 194. 1965; Tagawa & K.Iwats., Fl. Thailand 3: 412. 1988. – Pronephrium lakhimpurense (Rosenst.) Holttum, Blumea 20: 110. 1972; Boonkerd & Pollawatn, Pterid. Thailand: 226. 2000.

Dryopteris rubra Ching, Bull. Fan Mem. Inst. Biol. 2: 198, t. 12. 1931. – Abacopteris rubra (Ching) Ching, Bull. Fan Mem. Inst. Biol. 8: 245. 1938; Holttum, Dansk Bot. Ark. 20: 23. 1961. – Cyclosorus rubra (Ching) Tardieu ex Tardieu & C.Chr., Notul. Syst. 7: 76. 1938; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 390. 1941. – Thelypteris rubra (Ching) K.Iwats., J. Jap. Bot. 38: 315. 1963; Tagawa & K.Iwats., SouthE. Asian Stud. 3(3): 81. 1965; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 70. 1967.

Cyclosorus moulmeinensis auct. non (Bedd.) Copel.: Holttum, Dansk Bot. Ark. 23: 233. 1965.

Description

Rhizome creeping, 6–8 mm diam., blackish; scales oblong-ovate with tails, up to 5 by 1.3 mm, brown, hairy. Stipes 43–111 cm long, stramineous with dark scaly base. Laminae oblong, 40–105 by 25–50 cm; lateral pinnae (4–)6–9 pairs, subsessile, ascending, narrowly oblong, cuspidate at apex, rounded to broadly cuneate at base, subentire or irregularly undulate, 16–30 by 3.8–5.5 cm, aerophores present at rachis/costa junction, most conspicuous in crozier, basal pinnae reduced or not; thin, papyraceous to herbaceous, green to dark green, tinted red in dried specimens, glabrous to densely minutely pubescent beneath; venation meniscioid, or excurrent veins interrupted. Sori in two rows usually close to excurrent veinlets, round to oblong, often confluent at maturity, exindusiate; sporangia not setose , sometimes glands on sporangial body.

Distribution in Thailand

NORTHERN: Mae Hong Son, Chiang Mai, Chiang Rai, Tak, Phitsanulok; NORTH-EASTERN: Loei; SOUTH-WESTERN: Kanchanaburi, Phetchaburi.

Wider Distribution

Himalaya to SW China and N Vietnam.

Ecology

On humus-rich slopes usually near streams in 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. 5123, Loei, Phu Suan Sai National Park (E).