Cyclosorus canus (Baker) S.Linds.

Family

Thelypteridaceae

Nomenclature

Cyclosorus canus (Baker) S.Linds., Edinburgh J. Bot. 66: 359. 2009. – Nephrodium canum Baker, Syn. Fil. 267. 1867. – Dryopteris cana (Baker) Kuntze, Rev. Gen. Pl. 2: 812. 1891. – Pseudocyclosorus canus (Baker) Holttum & Jeff W.Grimes, Kew Bull. 34: 509. 1980. – Type:  Edgeworth s.n., NW India’ (holo K).

Nephrodium repens C.Hope, J. Bombay Nat. Hist. Soc. 12: 535, t. 8. 1899. – Thelypteris repens (C.Hope) Ching, Bull. Fan Mem. Inst. Biol. 6: 304. 1936; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 67. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 422, f. 43.5–6. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 230. 2000.  – Pseudocyclosorus repens (C.Hope) Ching, Acta Phytotax. Sin. 8: 324. 1963. – Type: C.W. Hope s.n., India, Kumaon, 22 July 1887 (lecto BM).

Description

Rhizome short creeping, about 3 mm diam.; scales about 4 mm long, pale brown, membranous, appressed, hairy. Stipes stramineous, with reduced pinnae, or auricled, nearly to base, 30–50 cm to first full-sized pinnae. Laminae oblong-lanceolate, acute at apex, narrowing towards base, 40–100 by 20–32 cm; pinnae 25–30 full-sized pairs, middle pinnae sessile, patent, linear-lanceolate, acute at apex, truncate and more or less auricled at base, deeply lobed, basal pinnae rather remote, reduced, 6–10 pairs; segments oblong, oblique, round to moderately acute at apex, entire and somewhat involute at margin; softly chartaceous, green; costa and rachis hairy; veins pinnate, veinlets simple, hairy. Sori medial, round; indusia persistent, hairy .

Distribution in Thailand

NORTHERN: Chiang Mai, Chiang Rai; EASTERN: Chaiyaphum.

Wider Distribution

Himalaya to SW China and N Vietnam.

Ecology

On wet sandy ground by streams or in paddy fields at medium altitudes.

Proposed IUCN Conservation Assessment

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

Notes

The illustration in the Flora of Thailand (Fig. 43.5) shows the pinnae gradually reducing downwards to very small.  We have not seen specimens that gradually reduce but rather the change is abrupt .

Voucher specimens - Thailand

 

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