taxonID	type	description	language	source
D93687A9FFC9FFEDD535FA8A3A80F932.taxon	etymology	Etymology. The specific epithet ‘ tenasserimensis ’ is derived from the Tenasserim Range to where the species is endemic. 1 Faculty of Environment and Resource Studies, Mahidol University (Salaya campus), Nakhon Pathom 73170, Thailand; corresponding author e-mail: thamarat. phu @ mahidol. ac. th. 2 Royal Botanic Garden Edinburgh, 20 A Inverleith Row, Edinburgh, EH 3 5 LR, Scotland, UK. Monoecious herb, 5 – 20 cm tall. Stems succulent, glossy, erect, glabrous, pale green or dark red; tubers globose or subglo- bose, 5 – 10 mm diam, with numerous fibrous roots. Stipules persistent, lanceolate, pale green 4 by 3 mm, with sparse glandular hairs. Leaves 3 – 5 per plant, basifixed, petiole pale green or maroon, reddish brown when dry, 1 – 5 cm long; leaf blade succulent, symmetric or subsymmetric, chartaceous when dry, adaxial surface sparsely hirsute, light green, glossy, iridescent, abaxially glabrous and glaucous; palmatifid, 4 – 7 by 4 – 8 cm, apex shallowly trilobed, margin dentate or biserrate with short spinose hairs, base truncate or rarely cordate; vena- tion palmate, main veins 3. Inflorescences terminal, 5 – 9 cm long, a compound dichasium, bisexual, 1 – 4 times branched with many staminate flowers and 1 pistillate flower per branch on the lowest branch, protandrous; peduncles 2 – 7 cm long, terete with glandular hairs, pale green or dark red, glossy. Bracts persistent, membranous, pale green, glossy, lanceolate, with sparse glandular hairs, 2 – 3 by 1 – 2 mm, apex obtuse, margin entire. Staminate flowers: pedicels 4 – 5 mm, erect, with glandu- lar hairs; tepals 4, pale magenta, outer 2 suborbicular, 4 – 6 by 4 – 5 mm, base rounded, apex obtuse, margin entire, glabrous on both sides; inner 2 lanceolate, 3 – 4 by 2 – 3 mm, base obtuse, apex acute, margin entire, glabrous on both sides; androecium zygomorphic, like bunch of bananas, stamens c. 18 – 20, yellow, filaments c. 0.5 mm long, anthers oblong c. 1 mm long, apex retuse, dehiscing by slits near the tip, filaments fused in a col- umn. Pistillate flowers: pedicels erect, pale magenta, 3 – 10 mm long; tepals 5, unequal, pale magenta, outer 2 orbicular, 4 – 6 by 4 – 5 mm, apex obtuse, margin entire, base rounded, gla- brous on both sides; inner 3 lanceolate or oblong, 3 – 4 by 2 – 3 mm, apex acute, margin entire, base obtuse, glabrous on both side; styles 3, fused halfway, yellow, stigmatic band irregularly crescent-shaped; ovary with 3 wings, with glandular hairs, 2 - locular, placenta bilamellate. Fruits with persistent tepals, glossy, pale green, pendulous, drying pale brown, c. 5 – 6 by 5 – 10 mm; locule elliptic, 3 – 4 by 3 – 5 mm, abaxial wing facing down, slightly larger than the lateral wings, 5 – 10 mm long. Seeds numerous, brown, barrel-shaped, c. 0.3 mm long. Distribution & Ecology — Peninsular Thailand (Satun Prov- ince, Thung Wa, Than Plew Waterfall, 140 m; Ranong Province, Raksra Warin hot water spring park, 100 m) and Myanmar (Tenasserim), in small crevices on eroded limestone rocks amongst numerous pools and small waterfalls in gallery forest. Flowering: July to November; fruiting: November to December. Conservation assessment — Begonia tenasserimensis is known only from two karst limestone localities in Thailand and one in Myanmar, the latter collected in 1861. Only 25 % of the 20,000 km 2 of karst limestone in Thailand is protected (Cle- ments et al. 2006). The Thai populations of the species are in localities classed as recreation areas (IUCN protected area category VI; an area which is promoted for sustainable use, where conservation and sustainable use can be mutually beneficial; IUCN 2016) and can receive many tourist visitors in the high season. The exact locality of the Myanmar collection is unknown. We consider a category of Vulnerable (VU D 2) to be appropriate, as the populations are prone to the effects of human activities or stochastic events within a very short period (IUCN 2012). Additional specimens examined. MYANMAR, Tenasserim, J. W. Helfer 2584 (K), 1861 – 2. – THAILAND, Ranong, C. Phengklai 1300 (BKF), 18 Sept. 1968.	en	Phutthai, T., Hughes, M. (2017): A new species of Begonia section Parvibegonia (Begoniaceae) from Thailand and Myanmar. Blumea 62 (1): 26-28, DOI: 10.3767/000651917X695083, URL: https://doi.org/10.3767/000651917x695083
