Adiantum stenochlamys Baker

Etymology

According to Holttum (1954), the botanical name, Adiantum (unwetted) refers to the way in which water-drops run off the surface of the pinnae without wetting them.

Family

Pteridaceae, subfamily Vittarioideae

Nomenclature

Adiantum stenochlamys Baker, Ann. Bot. 5: 209. 1891; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 187. 1940; Holttum, Rev. Fl. Malaya ed. 1, 2: 602, f. 353. 1955 [‘1954’]; Ching, Acta Phytotax. Sin. 6: 328. 1957; Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 50. 1968; Tagawa & K.Iwats., Fl. Thailand 3: 215, f. 16.5. 1985; Boonkerd & Pollawatn, Pterid. Thailand: 119. 2000; Newman et al., Checkl. Vasc. Pl. Lao PDR: 31. 2007.

Adiantum fragiliforme C.Chr., Bot. Tidsskr. 32: 347. 1916.

Adiantum suborbiculare Alderw., Bull. Dept. Agric. Ind. Neerl. 18: 11. 1908; E.Smith, J. Siam Soc. Nat. Hist. Suppl. 8: 3. 1929.

Description

Terrestrial or lithophytic. Rhizome short erect, bearing a dense tuft of fronds, covered with scales; scales linear, slightly broader at base, entire, 7–8 mm long, golden brown, concolorous. Stipes terete, not grroved above, 2–30 cm long, dark reddish brown to blackish, shiny, glabrous except for scales at baseLamina perfectly glabrous, tripinnate at base, 5.5–21 by 4.5–24 cm; rachis terete, glabrous, black; c.3 pairs of pinnate pinnae, basal pinnae 2.5–15 cm long; leaflets fan-shaped, 6–15 by 6–17 mm, base obtuse to acutedistal margin round, sometimes lobed, thin, glabrous, glaucous beneath or not, distinctly stalked; veins not raised. Sori marginal, square to elongate, 1–8 to each pinnule .

Distribution in Thailand

SOUTH-EASTERN: Trat; PENINSULAR: Surat Thani, Satun, Songkhla.

Distribution in Laos

Unspecified.

Distribution in Cambodia

Kampot, Kompong Speu, Pursat

Wider Distribution

Cambodia, Vietnam, Peninsular Malaysia, Borneo and Philippines.

Ecology

On wet rocks in forests usually at low altitudes near sea.

Proposed IUCN Conservation Assessment

Least Concern (LC). This species is common and widespread.

Notes

A very variable species .  Following the Flora of Thailand Adiantum fragiliforme is included in synonymy here but further taxonomic work is necessary to see if this decision is correct .

Voucher specimens - Thailand

Middleton et al. 4624 & 4626, Trat, Ko Chang, Trail from Khlong Phlu Ranger Station (E).

Voucher specimens - Cambodia

Schnell 10068, Kampot, Elephant Mts (P); Pierre 5747, Kompong Speu, Mt Aral (P); Mueller  526, Pursat (P).

Habit

Habit

Habit

Habit

Rhizome

Rhizome

Rhizome scales

Rhizome scales

Frond

Frond

Lamina

Lamina

Lamina from above

Lamina from above

Upper surface of pinnules

Upper surface of pinnules

Lamina from beneath

Lamina from beneath

Undersurface of lamina

Undersurface of lamina

Pinnules with young sori

Pinnules with young sori

Sori

Sori

Sori

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.