Family

Dryopteridaceae

Nomenclature

Dryopteris sparsa (D.Don) Kuntze, Rev. Gen. Pl. 2: 813. 1891; Ching, Bull. Fan Mem. Inst. Biol. 8: 470. 1938; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 318. 1941; Holttum, Rev. Fl. Malaya ed. 1, 2: 492, f. 292. 1955 [‘1954’]; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 95. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 352. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 159, 205. 2000. – Nephrodium sparsum D.Don, Prodr. Fl. Nepal.: 6. 1825. – Lastrea sparsa (D.Don) T.Moore, Index Filic.: 87, 104. 1858; Bedd., Handb. Ferns Brit. India: 252. 1883.

Description

Rhizome short, erect; scales membranous, light brown or the centre dark brown, oblong-ovate, about 10–13 by 4–8 mm, margin entire. Stipes castaneous at least towards base, stramineous above, densely scaly at base, sparsely so above, up to 35 cm long. Laminae oblong-subdeltoid, acuminate at apex, bipinnate to tripinnate at widest base, up to 50 by 25 cm; basal pinnae the largest, asymmetrically subtriangular, acuminate at apex, up to 20 by 12 cm; middle pinnae falcate, stalked, subtriangular-lanceolate; pinnules oblong, slightly falcate, rounded or moderately acute at apex, unequally cuneate at sessile base or decurrent at base in upper ones, up to 30 by 8 mm, lobed 1/3 way to midrib; basal basiscopic pinnule of lower pinnae large, about twice as large as the next one, pinnate; lobes oblong, oblique, rounded or moderately acute at apex, serrate at margin; papyraceous to chartaceous, deep green above, pale beneath; veins pinnate, veinlets simple, ending within margin of lobes. Sori dorsal on veinlets, costular or medial; indusia large, about 1.5 mm diam., glabrous, not persistent .

Distribution in Thailand

NORTHERN: Chiang Mai, Chiang Rai, Phitsanulok; NORTH-EASTERN: Loei; SOUTH-EASTERN: Chanthaburi; PENINSULAR: Nakhon Si Thammarat.

Wider Distribution

India, China, Indochina, throughout Malesia to Polynesia, Taiwan and north to S Japan.

Ecology

On mountain slopes in dense forests or in light shade at 1000–1500 m alt.

Similar species

Dryopteris rheophila Mitsuta ex Darnaedi, M.Kato & K.Iwats.

Proposed IUCN Conservation Assessment

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

Notes

Part of a species complex including Dryopteris rheophila Mitsuta ex Darnaedi, M.Kato & K.Iwats., the taxonomy of which requires clarification.

Voucher specimens - Thailand

Middleton et al. 5082, Phitsanulok, Phu Hin Rong Kla National Park. Trail to waterwheel (E); Middleton et al. 5156 & 5169, Loei, Phu Luang Wildlife Sanctuary (E).