Dryopteris sparsa (D.Don) Kuntze

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).

Habit

Habit

Longitudinal section through rhizome

Longitudinal section through rhizome

Stipe with scales

Stipe with scales

Pinnae

Pinnae

Upper frond surface

Upper frond surface

Upper frond surface

Upper frond surface

Lower frond surface and sori

Lower frond surface and sori

Young sori

Young sori

Old sori

Old sori

Site hosted by the Royal Botanic Garden Edinburgh. Content managed by Stuart Lindsay, Gardens by the Bay, Singapore and David Middleton, Singapore Botanic Gardens. Last updated 16 November 2016.