Davallia trichomanoides Blume var. trichomanoides

Family

Davalliaceae

Nomenclature

Davallia trichomanoides Blume, Enum. Pl. Javae: 238. 1828; Holttum, Rev. Fl. Malaya ed. 1, 2: 361. 1955 [‘1954’]; Holttum, Dansk Bot. Ark. 20: 25. 1961; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 76. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 162. 1985; Nooteboom, Fl. Males., Ser. II, Ferns and Fern Allies 3: 264. 1998; Boonkerd & Pollawatn, Pterid. Thailand: 171, 234. 2000. – Type: Blume s.n. (L sheet 908.332-946 holo), Java.

Davallia bullata Wall. ex Hook., Sp. Fil. 1: 169, t. 50B. 1846; Bedd., Handb. Ferns Brit. India: 61, f. 31. 1883.

Davallia petelotii Tardieu & C.Chr., Not. Syst. 6: 4, pl. 1, f. 5–7. 1937; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 104, f. 12.5–12.7. 1939; Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 49. 1968; Tagawa & K.Iwats., Fl. Thailand 3: 161, f. 12.3. 1985; Boonkerd & Pollawatn, Pterid. Thailand: 233. 2000; Newman et al., Checkl. Vasc. Pl. Lao PDR: 26. 2007. – Type: Petelot 4200, Laos, Xieng Khouang, Plaine des Jarres (P).

 

Davallia trichomanoides Blume var. trichomanoides

Description

Rhizome long creeping, 3–6 mm diam., densely scaly throughout; scales various as noted in the key to the varieties. Stipes stramineous or brownish, 10–25 cm long, glabrous except for the scaly base. Laminae oblong-subdeltoid, deltoid or roundly pentagonal, gradually narrowed from base to apex or acuminate, about 18 cm long and wide, or up to 35 cm long and 20 cm wide, tripinnate to quadripinnatifid; basal pinnae the largest, gradually narrowed from base to acute or acuminate apex, 10–15 by 6 cm, stalked about 1 cm long; upper pinnae gradually smaller upwards; pinnules subsessile or larger ones very shortly stalked, moderately acute to acute at apex, cuneate at base; secondary pinnules sessile, oblong-lanceolate or rhomboid, round to moderately acute at apex, cuneate at base, serrate to pinnatisect at margin; lobes acute at apex, subcoriaceous, glabrescent, green, paler beneath; veins pinnate, hardly distinct. Sori terminal on veinlets; indusia cup-shaped, up to 2 mm long, 0.7 mm diam.

There are two distinct varieties which are sometimes treated as species. As noted by Holttum (1955 [‘1954’]), the rhizome scales of var. trichomanoides are somewhat variable in colour and hairiness, though those of var. lorrainii are stable and discriminative by themselves.

Key to the varieties in Thailand

1. Scales gradually narrowing from peltate base to acuminate apex, bright brown, entire and nearly glabrous to short-hairy at margin. Ultimate segments lobed more than half-way towards midribs.   a. var. trichomanoides
1. Scales abruptly narrowing above the base to form long tails, dark except for those on young rhizome, with long paler hairs at margin; hairs longer than the breadth of scales, ultimate segments very shallowly lobed .  b. var. lorrainii

Distribution in Thailand

NORTHERN: Chiang Mai, Phitsanulok; PENINSULAR: Surat Thani.

Distribution in Laos

Xieng Khouang.

Wider Distribution

Sri Lanka, Himalayas, Indochina and Malesia.

Ecology

On high mossy branchlets of trees in evergreen forests on ridges or river banks at low to medium altitudes.

Proposed IUCN Conservation Assessment

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

Voucher specimens - Laos

Petelot 4200, Xieng Khouang, Plaine des Jarres (P).

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