Family

Thelypteridaceae

Nomenclature

Thelypteris dayi (Bedd.) B.K.Nayar & S.Kaur, Companion Handb. Ferns Brit. India: 59. 1974. – Nephrodium dayi Bedd., J. Bot. 25: 323. 1887 – Aspidium dayi (Bedd.) Bedd., J. Bot. 26: 4. 1888 – Lastrea dayi (Bedd.) Bedd., Suppl. Ferns Brit. Ind.: 54. 1892. – Metathelypteris dayi (Bedd.) Holttum in B.K.Nayar & S.Kaur, Companion Handb. Ferns Brit. India: 205. 1974. – Type: J.Day s.n., Peninsular Malaysia, Perak, March 1887 (K, barcode K000638046, lectotype designated by Holttum (Flora Malesiana, 1982)).

Thelypteris singalanensis auct. non (Baker) Ching: Tardieu & C.Chr., Fl. Indo-Chine 7(2): 365. 1941; Holttum, Rev. Fl. Malaya ed. 1, 2: 243, f. 138. 1955 [‘1954’]; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 63. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 399, f. 38.1–3. 1988. – Metathelypteris singalanensis auct. non (Baker) Ching: Boonkerd & Pollawatn, Pterid. Thailand: 225. 2000.

Description

Rhizome short, erect; scales very sparse, linear, up to 8 by 0.2 mm, dark brown. Stipes stramineous, up to 60 cm long, scaly and hairy at base when young, glabrescent upwards. Laminae about 60 by 35 cm, pinnate-bipinnatifid; pinnae sessile, linear-lanceolate, caudate-acuminate at apex, up to 20 by 3 cm; rachis and costa densely hairy on upper surface, glabrous below; pinnules narrowly oblong, patent to falcate, up to 15 by 4.5 mm, entire, rounded to moderately acute at apex; softly papyraceous to papyraceous, green; veins pinnate, veinlets simple, forked, or triforked, glabrous. Sori dorsal on veinlets, in a medial row between costules and margin of pinnules; indusia thin, glabrous .

Distribution in Thailand

NORTHERN: Phitsanulok; SOUTH-WESTERN: Phetchaburi; PENINSULAR: Nakhon Si Thammarat.

Wider Distribution

Vietnam, Peninsular Malaysia, Sumatra, Borneo and W Java.

Ecology

On mountain slopes in light shade or in evergreen forests at medium altitudes.

Proposed IUCN Conservation Assessment

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