Family

Polypodiaceae

Nomenclature

Phymatosorus membranifolius (R.Br.) S.G.Lu, Guihaia 19: 27. 1999. – Polypodium membranifiolium R.Br., Prodr.: 147. 1810. – Microsorum membranifolium (R.Br.) Ching, Bull. Fan mem. Inst. Biol. 10: 239. 1941; Nooteboom, Blumea 42: 339. 1997. – Type: Banks. s.n. (BM), Australia.

Polypodium nigrescens Blume, Enum. Pl. Javae: 126. 1828; Fl. Javae Fil.: t. 70. 1829; Christ, Bot. Tidsskr. 24: 105. 1901; C.Chr., Bot. Tidsskr. 32: 348. 1916. – Pleopeltis nigrescens (Blume) Carr. in Seem., Fl. Vit.: 368. 1873; Bedd., Handb. Ferns Brit. India: 367, f. 208. 1883. – Phymatodes nigrescens (Blume) J.Sm., Ferns Brit. For.: 94 1866; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 473. 1941; Holttum, Rev. Fl. Malaya ed. 1, 2: 193, f. 95. 1955 [‘1954’]; Holttum, Dansk Bot. Ark. 20: 21. 1961; Holttum, Dansk Bot. Ark 23: 231. 1965; Seidenf., Nat. Hist. Bull. Siam Soc. 19: 86. 1958. – Microsorum nigrescens (Blume) Copel., Occas. Pap. Bernice Pauahi Bishop Mus. 14: 74. 1938; Tagawa & K.Iwats., SouthE. Asian Stud. 3(3): 77. 1965; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 54. 1967; Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 53. 1968; Tagawa & K.Iwats., Fl. Thailand 3: 532. 1989. – Phymatosorus nigrescens (Blume) Pic.Serm., Webbia 28: 459. 1973; Boonkerd & Pollawatn, Pterid. Thailand: 282. 2000.

Polypodium alternifolium Willd., Sp. Pl. 5: 168. 1810. – Microsorum alternifolium (Willd.) Copel., Gen. Fil.: 197. 1947.

Phymatodes variabilis Ching, Bot. Mag. (Tokyo) 43: 3. 1929. – Phymatodes nigrescens var. variabilis (Ching) C.Chr. & Tardieu, Notul. Syst. (Paris) 8: 191. 1939; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 473. 1941.

Description

Rhizome creeping, thick, about 1 cm diam., scaly; scales circular to oblong, round to moderately acute at apex, round at base, attached near the centre, minutely hairy at margin, about 5 mm in both directions, brown, more or less clathrate with thick internal cell-walls and not transparent surface walls, the internal wall gradually becoming thinner outwards. Stipes up to 50 cm long, stramineous, glabrous. Laminae pinnatisect nearly to rachis, subdeltoid to oblong, up to 80 by 40 cm; lateral lobes longest at base, or the basalmost ones a little reduced, gradually becoming smaller upwards, up to 30 by 4.5 cm, more or less ascending, usually straight, caudately acuminate at apex, subentire and nearly parallel at margin, somewhat narrowing towards base, up to 12 pairs; veins all distinct, forming areoles; papyraceous. Sori round, in distinct hollow in one row at each side of costa , about 4 mm diam., distinctly raised on upper surface.

Distribution in Thailand

EASTERN: Chaiyaphum, Nakhon Ratchasima; SOUTH-WESTERN: Uthai Thani, Kanchanaburi, Phetchaburi, Prachuap Khiri Khan; SOUTH-EASTERN: Prachin Buri; Chanthaburi, Trat; PENINSULAR: Chumphon, Ranong, Phangnga, Nakhon Si Thammarat, Phatthalung, Trang, Satun, Pattani, Yala, Narathiwat.

Distribution in Cambodia

Kampot, Kompong Speu.

Wider Distribution

Sri Lanka, S India, Vietnam, Cambodia, throughout Malesia and Polynesia.

Ecology

On rather dry rocks in mixed forests at low altitudes.

Proposed IUCN Conservation Assessment

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

Voucher specimens - Thailand

Middleton et al. 4677, Chanthaburi, Khao Khitchakut National Park (E); Middleton et al. 4705, Chanthaburi, Khao Soi Dao Wildlife Sanctuary (E); Middleton et al. 4382, Nakhon Si Thammarat, Khao Luang National Park (E); Middleton et al. 5422, Phatthalung, Lan Mom Jui Waterfall (E).