Family

Dryopteridaceae

Nomenclature

Polystichum scariosum (Roxb.) C.V.Morton, Contr. U.S. Natl. Herb. 38(7): 359. 1974; Boonkerd et al., Thai For. Bull. (Bot.) 32: 8. 2004; Boonkerd & Pollwatn, Nat. Hist. J. Chulalongkorn Univ. 6: 22. 2006. – Polypodium scariosum Roxb., Calcutta J. Nat. Hist. 4: 494. 1844.

Polystichum prolificans Alderw., Bull. Jard. Bot. Buitenzorg, Ser. 3. 2: 170. 1920; Holttum, Rev. Fl. Malaya ed. 1, 2: 490, f. 290. 1955 [‘1954’]; Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 176. 1969; Tagawa & K.Iwats., Fl. Thailand 3: 336. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 209. 2000. – Polystichum eximium auct. non (Mett. ex Kuhn) C.Chr.: Tagawa & K.Iwats., SouthE. Asian Stud. 5: 94. 1967, p.p.

Description

Description from Holttum, Rev. Fl. Malaya ed. 1, 2: 490, f. 290. 1955 [‘1954’] under the synonym Polystichum prolificans Alderw.
Apex of stock and base of stipes densely covered with broad lanceolate scales; middle part of scales shining dark brown, the edges pale, dull, fimbriate. Stipes stout, to 60 cm long, the sub-basal part at least bearing numerous narrow pale brown scales. Laminae to 70 cm long and 35 cm wide, bipinnate, sub-basal pinnae largest, upper pinnae very gradually reduced, one of them bearing a bud in its axil. Pinnae to about 20 cm long and 5 cm wide at the base, shortly stalked, pinnate almost throughout; pinnules to 3.3 cm long, shortly stalked, falcate, the base auriculate on the acroscopic side, narrowly cuneate below, the edges above the basal auricle rather shallowly crenate-lobate, the apices of the lobes never aristate and often blunt; vein-groups in each lobe several times alternately forked, bearing several sori in the larger lobes, one only (apical on the acroscopic vein, rather near the costa) opposite the smaller distal lobes; indusium very small, firm, brown, peltate, not covering the sorus at maturity and apparently often falling away; texture of lamina subcoriaceous; rachises and lower surface bearing rather copious very narrow hair-like brown scales with a small round base .

Distribution in Thailand

SOUTH-WESTERN: Kanchanaburi, Phetchaburi; PENINSULAR: Phangnga, Nakhon Si Thammarat, Trang, Yala.

Wider Distribution

Peninsular Malaysia, Sumatra and Ambon (but see discussion in Morton, Contr. U.S. Natl. Herb. 38(7): 359. 1974).

Ecology

Terrestrial on humus-rich floor of dense evergreen forests at medium altitudes.

Proposed IUCN Conservation Assessment

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