taxonID	type	description	language	source
E40FC06650D2567AB8B7945660A520A7.taxon	diagnosis	Diagnosis. Morphologically similar to several Begonia having conically bullate leaves and others with a rugulose leaf surface with white maculation and a ciliolate tepal margin, but can be easily distinguished from them by the dendritic hairs on the petioles, abaxial veins and the keeled mid-rib of the stipules, glabrous peduncles, pistillate flowers with 2 tepals and glabrescent ovaries with verrucose wings.	en	Dong, Li-Na, Nguyen, Khang Sinh, Shui, Yu-Min, Nguyen, Hieu Quang, Xu, Wei-Bin, Nguyen, Xuan Khu (2021): Begonia catbensis (sect. Coelocentrum, Begoniaceae), a new species from northern Vietnam. PhytoKeys 179: 1-12, DOI: http://dx.doi.org/10.3897/phytokeys.179.65812, URL: http://dx.doi.org/10.3897/phytokeys.179.65812
E40FC06650D2567AB8B7945660A520A7.taxon	materials_examined	Type. Vietnam. Hai Phong City, Cat Hai District, Cat Ba National Park, remnants of primary broad-leaved evergreen forest in lowland of limestone hills, around point 20.803333 ° N, 106.999167 ° E, 50 - 70 m a. s. l., flowers white to greenish, fruits green, rare, 24 August 2019, W. B. Xu, K. S. Nguyen, C. R. Lin, L. N. Dong, H. Q. Nguyen & X. K. Nguyen 14002 (Holotype: HN!; Isotypes: IBK 00421271!, HN!).	en	Dong, Li-Na, Nguyen, Khang Sinh, Shui, Yu-Min, Nguyen, Hieu Quang, Xu, Wei-Bin, Nguyen, Xuan Khu (2021): Begonia catbensis (sect. Coelocentrum, Begoniaceae), a new species from northern Vietnam. PhytoKeys 179: 1-12, DOI: http://dx.doi.org/10.3897/phytokeys.179.65812, URL: http://dx.doi.org/10.3897/phytokeys.179.65812
E40FC06650D2567AB8B7945660A520A7.taxon	description	Description. Herb perennial, monoecious, epipetric, rhizomatous, rooting at nodes, about 25 - 35 cm tall. Rhizome succulent, elongate, 10 - 30 cm long, 4 - 7 mm in diameter, creeping and slightly suberect apically, pale greenish to purplish-green or brownish-red, internodes ca. 1.5 cm long, covered by sparse dendritic hairs. Stipules often persistent, ovate-triangular, herbaceous, brownish-red or purplish when young, later turning pale greenish speckled with purplish patches, 12 - 16 x 6 - 12 mm, adaxially glabrous, abaxially keeled, mid-rib with sparse dendritic hairs; margin entire or somewhat undulate and recurved; apex aristate, arista 2 - 3 mm long. Petiole cylindrical, succulent, 7 - 16 cm long, 3 - 4 mm in diameter, densely covered with reddish long-stalked dendritic hairs. Leaves 9 - 27, basal, alternate, asymmetric, unlobed, broadly ovate, 10 - 13 x 5 - 7 cm, papery, adaxially glossy, dark green or rarely brown, with slightly silvery green patches along the veins, surface densely bullate, bullae conical and tipped with a red seta 1.5 - 2 mm long, abaxially brownish-red to red-brown (maroon), with pale green along major veins, long-stalked reddish dendritic hairs along the veins, base strongly oblique-cordate, margin repand and serrulate with red setae 1.5 - 2 mm long, apex acuminate; venation palmate with 5 - 7 primary veins, mid-rib distinct, with 2 - 4 secondary veins on each side, tertiary veins reticulate or percurrent, minor veins reticulate. Inflorescences axillary, dichasial cymes branched 2 - 3 times, arising directly from rhizome, pedunculate; peduncle terete, 13 - 22 cm long, 2.5 - 3.5 mm thick, glabrous, pale greenish-red to red; bracts and bracteoles not caducous, oblong or oval to ovate, slightly concave at the base and distally bent outwards during flowering, pale green with several longitudinal reddish veins, margin serrate-fimbriate with cilia 1.5 - 3 mm long, bracts 8 - 10 x 4 - 6 mm, slightly larger than bracteoles (6 - 8 x 2.5 - 3.5 mm). Staminate flower: pedicel glabrous, 12 - 19 mm; tepals 4, pure white, outer 2 broadly ovate to suborbicular, 9 - 14 x 8 - 12 mm, sparsely puberulent at the proximal margin, inner 2 glabrous, elliptic to oblanceolate, 6 - 8 x 2.8 - 3.8 mm; androecium actinomorphic, spherical, 5 - 6 mm in diameter; stamens 27 - 32; filaments glabrous, 1.2 - 1.9 mm long, fused at base, yellowish dull white; anthers somewhat greenish-yellow, narrowly obdeltoid, 1.2 - 1.5 mm long, widest at apex, 0.8 - 1 mm wide, apex obtuse, base cuneate, opened by two longitudinal slits with orange margins. Pistillate flowers: pedicel glabrous, 7 - 14 mm long; tepals 2, suborbicular, 8 - 10 mm in diameter, greenish-white when young, later turning to dull white or pure white, glabrous, margin entire or slightly undulate with sparsely puberulent at base; ovary green, glabrescent, with verrucose wings, trigonous-ellipsoid, 1 - loculed; placentation parietal, with 3 placentae, each 2 branched; styles 3, fused at base or nearly free, glabrous, glossy, yellow, 3 - 5 mm long, apically C-shaped, stigmatic band twisted. Capsule nodding on a stipe 9 - 16 mm long, trigonous-ellipsoid, 13 - 18 mm long, 6 - 8 mm thick (wings excluded), fleshy, greenish when fresh, 3 - winged; wings densely verrucose, unequal, abaxial crescent shaped, 7 - 9 mm wide, lateral 2.5 - 3.5 mm wide. Seeds numerous, ellipsoid, brown.	en	Dong, Li-Na, Nguyen, Khang Sinh, Shui, Yu-Min, Nguyen, Hieu Quang, Xu, Wei-Bin, Nguyen, Xuan Khu (2021): Begonia catbensis (sect. Coelocentrum, Begoniaceae), a new species from northern Vietnam. PhytoKeys 179: 1-12, DOI: http://dx.doi.org/10.3897/phytokeys.179.65812, URL: http://dx.doi.org/10.3897/phytokeys.179.65812
E40FC06650D2567AB8B7945660A520A7.taxon	etymology	Etymology. The species is named after the type locality, Cat Ba National Park.	en	Dong, Li-Na, Nguyen, Khang Sinh, Shui, Yu-Min, Nguyen, Hieu Quang, Xu, Wei-Bin, Nguyen, Xuan Khu (2021): Begonia catbensis (sect. Coelocentrum, Begoniaceae), a new species from northern Vietnam. PhytoKeys 179: 1-12, DOI: http://dx.doi.org/10.3897/phytokeys.179.65812, URL: http://dx.doi.org/10.3897/phytokeys.179.65812
E40FC06650D2567AB8B7945660A520A7.taxon	distribution	Distribution and habitat. Cat Ba National Park is composed by many islets. All islets here are limestone mountains. We have had several days to survey in Cat Ba National Park and asked guides working in this National Park for the existence of this species, but we only found and recorded a single population here. Perhaps more populations will be found if more fieldwork is done in the future in this National Park. So far, Begonia catbensis is only known from the Cat Ba National Park, Cat Hai District, Hai Phong City, in northern Vietnam. Within its distribution area, the new species grows on semi-shady tops of small rocks and on steep slopes under the broad-leaved evergreen forest in lowlands of limestone hills.	en	Dong, Li-Na, Nguyen, Khang Sinh, Shui, Yu-Min, Nguyen, Hieu Quang, Xu, Wei-Bin, Nguyen, Xuan Khu (2021): Begonia catbensis (sect. Coelocentrum, Begoniaceae), a new species from northern Vietnam. PhytoKeys 179: 1-12, DOI: http://dx.doi.org/10.3897/phytokeys.179.65812, URL: http://dx.doi.org/10.3897/phytokeys.179.65812
