taxonID	type	description	language	source
03DF2916F8338F7BFCCBFF29FEC4FDCC.taxon	materials_examined	Type: — VIETNAM. Central Vietnam, Quang Nam province, Tay Giang district, A Tieng village, secondary evergreen broadleaved forest, occasionally on the slopes of stream valleys in moist places with soil rich in humus, around point 15 ° 54 ' 25 " N, 107 ° 29 ' 54 " E, elevation of about 600 m a. s. l., 08 September 2024, V. H. Bui BVHQN 80924 (holotype VNMN; isotype VNF). Monoecious herb, rhizomatous initially and becoming stoloniferous. Rhizome creeping, maroon to purplish-red, 6 – 9 mm thick, internodes up to 6 cm long, scattered with white to pale reddish-brown retrorse hirsute; aerial stems seen only at anthesis, usually 1 node, internodes ca. 15 cm long, 4 – 5.5 mm thick, very sparsely retrorse hirsute. Stipules persistent, maroon to purplish-red, triangular, 8 – 12 × 5 – 7 mm, herbaceous, strongly keeled, adaxially hirsute or villous along midrib, margin entire or sparsely denticulate with fimbriate, apex aristate, arista up to 5 mm long. Leaves alternate, oblique, slightly pointing upward; petiole terete, maroon to purplish-red, 15 – 30 cm long, 4 – 5.5 mm diameter, densely white to pinkish-brown retrorse hirsute or retrorse appressed-hirsute; leaf blade asymmetric, oblique, ovate to lanceolate-ovate, 13.5 – 21.5 × 5.5 – 9 cm, broad side 3.5 – 5 cm wide, basal lobes cordate, 1.3 – 1.8 cm long, apex short caudate, margin subentire to crenate, slightly recurved with a line of hirsute; leaf thick chartaceous to thinly coriaceous, succulent, adaxially dark blueish-green to olive green tinged brownish-red, glabrous, waxy, with moderately densely minutely depressed dots, rugose-bullate, giving a strongly wrinkled texture; abaxially pale purplish-green to magenta; venation palmate-pinnate, midrib distinct, ca. 3 secondary veins on each side, other primary veins branching dichotomously or nearly so, tertiary veins reticulate; major veins crimson or reddish-green adaxially, all veins purplish-red and scattered with hirsute-villous abaxially; leaves of erect stem similar to terrestrial leaves but smaller. Inflorescence protandrous, axillary, cymose arising directly from the rhizome or on an erect stem, 2 or 3 orders of branching; peduncle 7.5 – 11.5 cm long, purplish-red, erect, pale reddish-brown retrorse hirsute, sometimes subglabrous; bracts crimson to greenish-red, hyaline, semi-persistent, ovate, first pair 5 – 7 × 3.5 – 4 mm, decreasing in size towards the more distal inflorescence nodes, abaxially hirsute, margin fimbriate, acute and aristate at apex, arista ca. 1 mm long. Staminate flower: pedicel brownish-pink, ca. 17 mm long, sparsely hirsute; tepals 4, outer 2 pinkish-white with pale greyish-pink veins, widely ovate, 17 – 20 × 18 – 19 mm, margin entire, abaxially white to pink hirsute; inner 2 white or pinkish-white, widely obovate to suborbicular, apex round, base cuneate, 15 – 16 × 13 – 14 mm, glabrous; androecium actinomorphic, ca. 6 mm diameter; stamens ca. 70, yellow, filaments free, ca. 1.8 mm long, anthers obovate, ca. 1.5 mm long, 2 - locular, apex obtuse to rounded. Pistillate flower: not seen. Capsule pedicel ca. 3 cm long, very sparsely hirsute to subglabrous; ovary body trigonous-ellipsoid, 2 - locular, 14 – 16 mm long, 5 – 6 mm thick (wings excluded), subglabrous; wings unequal, crescent-shaped, lateral wings ca. 6 mm wide, abaxial wing 17 – 22 mm wide. Additional specimens examined: — VIETNAM. Quang Nam province: Tay Giang district, A Xan village, primary evergreen broad-leaved forest, around point 15 ° 81 ' 58 " N, 107 ° 33 ' 06 " E, elevation of about 1,300 m a. s. l., 20 April 2022, C. H. Nguyen, K. S. Nguyen, H. X. Cao, CKH 2022042079 (VNF).	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F8338F7BFCCBFF29FEC4FDCC.taxon	distribution	Distribution and ecology: — Begonia quangnamensis is currently only known from a single forest area in A Tieng and A Xan commune, Tay Giang district, Quang Nam province, central Vietnam (Fig. 11). The new species usually grows in moist shady places near waterfalls, along streams and occasionally on the slopes of stream valleys in moist places with soil rich in humus covered by evergreen broad-leaved forests at elevations of 600 – 1,300 m a. s. l. Flowers in August – October.	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F8338F7BFCCBFF29FEC4FDCC.taxon	etymology	Etymology: — The specific epithet is derived from Quang Nam province, the type locality of this new species. Conservation status: — The field studies conducted around the type location revealed no other populations outside the estimated occupancy area of approximately 5 km ². The type location comprises approximately 100 mature individuals growing in moist, shady places near waterfalls and along the stream. Given the small population size and the ongoing threats from road construction and agricultural expansion, which have led to the degradation of this fragile habitat, we propose that the new species should be preliminarily assessed as Critically Endangered (CR B 1 a, b (iii) 2 a + C 1) according to the IUCN criteria (2024). Notes: — Based on the observed morphological characteristics, such as a rhizomatous habit, anthers with a rounded apex, fruit with an enlarged adaxial wing, and a 2 - loculed ovary, we propose placing this species within sect. Platycentrum. Begonia quangnamensis can be distinguished by its rhizomes with elongate stolons, long-petioled leaves with a wrinkled texture that often appear slightly upward-pointing, and petioles covered in retrorse appressed hairs. This combination of characters is unique among the known begonias of Indochina. The new species somewhat similar to B. hongiaoensis Lin et al. (2021: 78), sharing the stoloniferous habit, long-petioled ovate leaves, and actinomorphic androecium in the staminate flowers. However, B. quangnamensis is distinguished by several key morphological differences: its petioles are covered in retrorse appressed-hirsute hairs (vs. minutely appressed-tomentose in B. hongiaoensis), leaf blade rugose-bullate (vs. flat), hirsute-villous on all veins of abaxial surface (vs. sparsely appressed tomentose, glabrescent), and tepals of staminate flowers hirsute (vs. glabrous) on the outside. A recently described species from Myanmar, B. persistens Maw et al. (2021: 215), shares several characteristics with B. quangnamensis, such as upward-pointing ovate foliage and 4 - tepaled staminate flowers with an actinomorphic androecium. Nonetheless, these two species are readily distinguishable: B. quangnamensis has longer petioles 21 – 30 cm (vs. 9 – 15 cm) long, terete (vs. narrowly winged on both sides), and covered in retrorse appressed-hirsute (vs. densely to sparsely tomentose), leaf blade lower side hirsute-villous on all veins (vs. tomentose), retrorse appressed-hirsute (vs. tomentose) peduncle, and smaller outer tepals of the staminate flowers, measuring 17 – 20 × 18 – 19 mm (vs. 12 – 13 mm) across.	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F8368F78FCCBFD52FE24FDBF.taxon	materials_examined	Type: — VIETNAM. Northern Vietnam, Thai Nguyen province, type herbarium specimens were prepared from cultivated plants on 20 October 2024 by Che Wei Lin, C. W. Lin 728 (holotype: TAIF). Rosette, monoecious rhizomatous herb. Rhizome stout, dusky orangish-red to brownish-red, 6 – 10 mm thick, internodes 3 – 30 mm or longer, densely white villous-hirsute. Stipules persistent, orangish-red to pale reddish-brown, triangular-ovate, 10 – 16 × 6 – 10 mm, herbaceous, more or less cucullate, strongly keeled, abaxially densely red to white villous-hirsute, margin fimbriate, apex aristate, arista ca. 2 mm long. Leaves alternate, oblique, held horizontally; petiole terete, creamy green to brownish-pink, 8 – 22 cm long, 3.5 – 6 mm diameter, densely white villous-hirsute; leaf blade asymmetric, oblique, widely ovate to widely oblong-ovate, 13 – 20 × 9.5 – 15 cm, broad side 5.3 – 9.5 cm wide, basal lobes cordate, 3 – 7 cm long, apex acuminate to attenuate, margin denticulate with a line of pinkish-white hirsute, sometimes serrate and irregularly shallowly triangular lobes; leaf chartaceous, succulent, adaxially dark olive green to bronzy purplish-green, embellished with a wide emerald green to silvery green band running parallel to the margin; upper surface densely covered by small raised cones each topped by a pinkish-white hirsute, giving a wrinkled texture; abaxially pale green, with a patch of purplish-red corresponding to the pattern on adaxial surface; venation basally ca. 8 palmate, midrib distinct, ca. 2 secondary veins on each side, other primary veins branching dichotomously or nearly so, tertiary veins reticulate; densely white to magenta villous-hirsute on all veins abaxially. Inflorescence protandrous, terminal or axillary on upper leaf axils, bisexual, cymose arising directly from the rhizome, up to 7 orders of branching; peduncle 2.3 – 7 cm long, orangish-red to brownish-red, erect, densely white to pink villous-hirsute; bracts orangish-red to pale reddish-brown, hyaline, semi-persistent, ovate to triangular-ovate, more or less cucullate, abaxially densely red to white villous-hirsute, margin entire or nearly so, acute and mucronate at apex; first pair 8 – 11 × 5 – 6.5 mm, decreasing in size towards the more distal inflorescence nodes. Staminate flower: pedicel creamy pink, 14 – 25 mm long, red hispid-hirsute; tepals 4, pink, outer 2 orbicular to widely ovate, sometimes widely oblong-obovate, 10 – 13.5 × 10 – 12 mm, margin entire, abaxially red hispid-hirsute; inner 2 lanceolate to lanceolate-elliptic, apex obtuse, 7 – 11 × 3.5 – 4.5 mm, glabrous; androecium zygomorphic, ca. 3.5 mm diameter; stamens 22 – 50, lemon yellow, filaments free, 1 – 1.5 mm long, anthers obovate, ca. 1 mm long, 2 - locular, apex obtuse to rounded-truncate. Pistillate flower: pedicel creamy pink to pinkish-white, 11 – 17 mm long, red hispid-hirsute; tepals 5, pale pink, outer 4 oblong-elliptic to widely elliptic-lanceolate, 10 – 15 × 5 – 8.5 mm, red hispid-hirsute abaxially; inner 1 elliptic to oblong, 7 – 12 × 2 – 4 mm, glabrous; ovary creamy white to pale pink, trigonous-globose, 3 – 5 mm long, 4 – 6 mm thick (wings excluded), red hispid-hirsute; 3 - winged, wings unequal, 4 – 7 mm long, pale creamy pink to pale yellowish-green, triangular, sometimes hooklike towed at the tip, rounded proximally, truncate distally, red hispid-hirsute, margin entire; larger 2, 3 – 7 mm wide, smaller 1, 2 – 3 mm wide; ovary 3 - locular, placenta bilamellate; styles 3, ca. 3.5 mm long, yellow, shortly fused at base, stigmatic band U-shaped and spirally twisted. Capsule not seen.	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F8368F78FCCBFD52FE24FDBF.taxon	distribution	Distribution and ecology: — Begonia zonata is currently only found exclusively in Thai Nguyen province, northern Vietnam (Fig. 11). It thrives on slopes with stony soils or rocky cliff faces within shaded areas of mixed broad-leaved and bamboo forests, at elevations reaching up to 800 m.	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F8368F78FCCBFD52FE24FDBF.taxon	etymology	Etymology: — The specific epithet ‘ zonata ’ refers to the plant's distinctive maroon foliage, marked by a green ring pattern. Conservation status: — A comprehensive botanical survey of the area has yet to be conducted, leaving us with limited knowledge about the species’ distribution. As such, we currently classify it as Data Deficient (IUCN 2024). Notes: — Begonia zonata is an attractive new species known for its bicolored, rugose foliage and multi-flowered inflorescences with delicately rosy pink flowers, making it popular among plant enthusiasts and widely cultivated in greenhouses. Superficially, it resembles B. versicolor Irmscher (1939: 546) and B. aurora Liu et al. (2020: 3) in having rugose leaves, 4 - tepaled staminate flowers, and 5 - tepaled pistillate flowers. However, B. zonata differs from B. versicolor by having a multi-branched inflorescence with up to 7 (vs. 2 or 3) branches, a zygomorphic (vs. actinomorphic) androecium, and a 3 - loculed (vs. 2 - loculed) ovary. It is further distinguished from B. aurora by its densely villous-hirsute (vs. velutinous along the midrib) stipules, fimbriate (vs. entire) margins, pink (vs. white) tepals in both staminate and pistillate flowers, a zygomorphic (vs. actinomorphic) androecium, and having 22 – 50 (vs. approximately 90) stamens.	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F8358F75FCCBFD9AFBC6FEED.taxon	materials_examined	Type: — VIETNAM. Northern Vietnam, Son La province, Thuan Chau distinct, Chieng Pac village, secondary evergreen broadleaved forest, occasionally in shady places on middle part of mountain slopes, around point 21 ° 24 ' 37 " N, 103 ° 47 ' 40 " E, elevation of about 750 m a. s. l., 24 October 2024, B. V. Huong BVHSL 241024 (holotype VNMN; isotype VNF). Monoecious tuberous herb. Stem tuberous at base, tubers globose or sub-globose with numerous fibrous roots, erect stem absent. Stipules persistent, very shallowly triangular, 1.8 – 3 × 4 – 5 mm, herbaceous, slightly keeled, margin sparsely denticulate, sometimes ciliate. Leaves 2 – 4, alternate, held horizontally; petiole terete, dusky purplish-red to brownish-red, 1.8 – 13 cm long, 1.5 – 5 mm diameter, sparsely tomentose-puberulous; leaf blades symmetric or subsymmetric, slightly oblique, ovate to widely ovate-triangular, 2.8 – 19 × 2.5 – 14.5 cm, broad side 1.6 – 8 cm wide, basal lobes cordate, 0.8 – 5.2 cm long, apex acute to obtuse or attenuate, margin subentire to sparsely denticulate and ciliate, recurved; leaf chartaceous, succulent, adaxially olive green to malachite green with tinged dark blueish-green to dark brown between tertiary veins, subvelutinous, sparsely to moderately densely puberulous or tomentose-puberulous; abaxially dark magenta, sometimes yellowish-green along veins, sparsely to densely tomentose-puberulous on all veins; venation basally 6 – 8 palmate, 2 or 3 major lateral veins on either side of midrib, other primary veins branching dichotomously, tertiary veins reticulate. Inflorescences protandrous, 1 – 3 on one plant, terminal, bisexual, up to 4 orders of branching; peduncle 2.5 – 8 cm long, purplish-red to brownish-red tinged olive green, erect, glabrous or subglabrous; bracts at lowmost one or two nodes (absent flower) persistent, narrowly triangular, 2.5 – 3.5 × 1 – 1.5 mm, margin minutely denticulate and ciliate; bracts at upper nodes (with flowers) deciduous, whitish-green, widely elliptic to obovate-elliptic or oblong, sometimes lanceolate-elliptic, 3.5 – 7 × 2 – 5 mm, margin subentire to sparsely denticulate, sometimes with sparsely gland-tipped hairs, decreasing in size towards the more distal inflorescence nodes. Staminate flower: pedicel 5 – 10 mm long, sparsely to densely gland-tipped puberulous, tepals 2, rosy pink, widely ovate to suborbicular, 7 – 12 × 8.5 – 10 mm, glabrous; androecium zygomorphic, ca. 4 mm across; stamens golden yellow, 10 – 15; filaments fused at base; anthers obovate, ca. 2 mm long, 2 - locular, apex acute to mucronate, longer than filaments. Pistillate flower: pedicel ca. 6 mm long, gland-tipped puberulous, tepals 3, rosy pink, glabrous, outer 2 widely ovate to suborbicular, 6 – 8 × 6 – 10 mm, inner 1 elliptic-lanceolate, 5 – 6 × 1 – 2 mm; ovary trigonous-ellipsoid, ca. 4.5 mm long, 3 – 4 mm thick (wings excluded), bright pink, very sparsely gland-tipped puberulous, apically beaked, the beak ca. 2 mm long; 3 - winged, wings unequal, pink, 5 – 7 mm long, very sparsely gland-tipped puberulous; lateral wings very narrowly crescent-shaped, ca. 0.5 mm wide, abaxial wing very narrowly trapezoid, ca. 1 mm wide, slightly pointed distally; ovary 3 - locular, placenta unilamellate; styles 3, fused at base, yellow, ca. 2 mm long, stigmatic band C-shaped and spirally twisted. Capsule not seen.	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F8358F75FCCBFD9AFBC6FEED.taxon	distribution	Distribution and ecology: — Begonia thuanchauensis is currently only known from a single forest area in Chieng Pac commune, Thuan Chau district, Son La province, northern Vietnam (Fig. 11). The new species usually grows in shady places on middle part of mountain slopes covered by evergreen broad-leaved forests at elevations of 600 – 700 m a. s. l. Flowers in September – November.	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F8358F75FCCBFD9AFBC6FEED.taxon	etymology	Etymology: — The specific epithet is derived from Thuan Chau district, the type locality of this new species. Conservation status: — Since no special surveys were carried out for delimiting its distribution, and the information about threat is unclear, so this species was considered as meeting the criteria of Data Deficient (DD) in terms of IUCN Red list categories and criteria (IUCN 2024). Notes: — The new species resembles Begonia qingchengshanensis Li et al. (2018: 198) in its tuberous habit, symmetric or subsymmetric leaf blades, 3 - tepaled pistillate flowers and unilamellate placenta. However, B. thuanchauensis differs in several aspects. It is acaulescent (vs. caulescent), and has leaf lamina puberulous (vs. glabrous), margins subentire to sparsely denticulate and recurved (vs. biserrate, flat), staminate flowers with 2 tepals (vs. 4), and pedicels gland-tipped puberulous (vs. glabrous or very sparsely tomentose).	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F8388F72FCCBFEABFE82FE81.taxon	materials_examined	Type: — VIETNAM. Northern Vietnam, Phu Tho province, type herbarium specimens were prepared from cultivated plants on 5 October 2024 by Che Wei Lin, C. W. Lin 727 (holotype: TAIF). Rosette, monoecious rhizomatous herb. Rhizome stout, reddish-brown, ca. 10 mm thick, internodes congested, subglabrous. Stipules persistent, whitish-green to pinkish-yellow, triangular, 5 – 8 × 4 – 7 mm, herbaceous, keeled, glabrous or very sparsely hirsute on base of midrib abaxially, margin entire or very sparsely minute denticulate, apex aristate, arista ca. 3 mm long. Leaves alternate, oblique, held horizontally; petiole terete, brownish-red, 4.5 – 11.5 cm long, 2.5 – 3 mm diameter, white to pinkish-white villous; leaf blade asymmetric, widely ovate to suborbicular, 7.5 – 15.5 × 6 – 11.5 cm, broad side 3.3 – 8 cm wide, basal lobes cordate, 2.4 – 6 cm long, apex acute to obtuse, margin crenulate with a line of white or rosy pink hispid-hirsute; leaf thick chartaceous, succulent, adaxially pale greyishgreen to silvery grey, with maroon to dark brownish-green zones extending along the primary veins, covering up to half to three-quarters of their length, and emicontinuous maroon stripes along the tertiary veins near the margins; adaxially slightly bullate, subvelutinous, sparsely white to pink hispid-hirsute; abaxially pale pinkish-green to greyish-pink, with magenta stripes aligned to the adaxial surface pattern, veins brownish-pink to magenta; venation basally ca. 7 palmate, midrib distinct, ca. 2 secondary veins on each side, other primary veins branching dichotomously or nearly so, tertiary veins reticulate; densely rosy pink villous and hispid-hirsute on all veins abaxially. Inflorescence protandrous, axillary, bisexual, cymose arising directly from the rhizome, up to 5 orders of branching; peduncle 5 – 11 cm long, pale green to rosy red, erect, glabrous; bracts creamy greenish-white to pale greenish-pink, hyaline, deciduous, suborbicular to elliptic-oblong, first pair up to 6.5 × 5 mm, decreasing in size towards the more distal inflorescence nodes, margin entire, apex obtuse to acute. Staminate flower: pedicel pale greenish-white to pink, 20 – 25 mm long, glabrous; tepals 4, white or pinkish-white, glabrous; outer 2 suborbicular to ovate, 9 – 12 × 8 – 10 mm, margin entire, apex rounded; inner 2 oblanceolate, apex rounded to truncate, 7.5 – 10 × 2.5 – 4 mm; androecium zygomorphic, ca. 4 mm diameter; stamens 16 – 30, yellow, filaments free, 1 – 1.5 mm long, anthers obovate-oblong, ca. 1 mm long, 2 - locular, apex truncate to rounded. Pistillate flower: pedicel pale greenish-white to pink, ca. 15 mm long, glabrous; tepals 3, white or pinkish-white, glabrous; outer 2 suborbicular to obovate, 8.5 – 11 × 8 – 9 mm, margin entire, apex rounded, inner 1 oblanceolate, ca. 8 × 3.5 mm, apex obtuse to rounded; ovary trigonous-ellipsoid, ca. 10 mm long, 3.5 mm thick (wings excluded), pale green to rosy pink, glabrous; 3 - winged, wings unequal, pale green to rosy pink, glabrous, margin entire; wings narrowly triangular to trapezoid, acute proximally, rounded to obtuse distally, ca. 10 mm long; lateral wings narrower, ca. 3 mm wide, abaxial wing ca. 5 mm wide, sometimes with 1 very reduced wings running parallel along the one side of the ovary; ovary 1 - locular with intruded parietal placentation, placentae 3, bilamellate; styles 3, fused at base, golden yellow, ca. 3.5 mm long, stigmatic band U-shaped and spirally twisted. Capsule body trigonous-ellipsoid, ca. 12 × 15 mm (wings included).	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F8388F72FCCBFEABFE82FE81.taxon	distribution	Distribution and ecology: — Begonia lii is endemic to Phu Tho province in northern Vietnam (Fig. 11), where it grows on limestone cliffs and boulders in semi-shaded areas at elevations up to 500 m.	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F8388F72FCCBFEABFE82FE81.taxon	etymology	Etymology: — The specific epithet honors Mr. Weng-Feng Li, an plant enthusiast who cultivated and provided material of this new species. Conservation status: — Begonia sect. Coelocentrum is adapted to limestone environments and has a highly restricted distribution, we consider it a rare endemic species, likely confined to only a few limestone hills in Phu Tho province. However, detailed information on its habitat and population status remains lacking. In light of the limited data, we classify B. lii as Data Deficient (IUCN 2024). Notes: — Begonia lii resembles B. lui Liu et al. (2020: 15) from China, which is also a member of sect. Coelocentrum. Both species share several morphological characteristics, including widely ovate to suborbicular foliage, villous petioles, glabrous tepals in both staminate and pistillate flowers, and a zygomorphic androecium. However, B. lii is sharply distinct due to its sparsely hispid-hirsute (vs. moderately densely setulose) upper surface of the lamina, entire (vs. fimbriate) bract margins, obtuse to rounded anther apices (vs. retuse), narrowly triangular (vs. crescent-shaped) ovary wings, and a U-shaped, spirally twisted (vs. C-shaped, less pronounced helicoid) stigmatic band. Among Vietnamese species, it also shares similarities with B. babeana Averyanov & Nguyen (2012: 7), but can be distinguished by its larger (7.5 – 15.5 × 6 – 11.5 cm vs. 4 – 6 × 3 – 4.5 cm) leaves, slightly bullate (vs. strongly rugose-bullate) upper surface, zygomorphic (vs. actinomorphic) androecium, and narrowly triangular (vs. crescent-shaped) ovary wings.	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F83F8F6FFCCBFE8EFC3BFA0C.taxon	materials_examined	Type: — VIETNAM. Southern Vietnam, Binh Thuan province, Tanh Linh district, Duc Phu village, primary evergreen broad-leaved forest, around point 11 ° 17 ' 56 " N 107 ° 41 ' 13 " E, elevation of about 550 m a. s. l., 21 October 2024, D. M. Vu VMD 211024 (holotype VNF). Monoecious rhizomatous herb. Rhizome stout, dusky crimson to brownish-red, 3 – 8 cm or longer, 5 – 8 mm thick, internodes 1 – 6 mm long, hirsute and tomentose; erect stems seen only at anthesis, 1 or 2 nodes, crimson, internodes 1 – 6.5 cm long, 2 – 6 mm thick, tomentose to villous. Stipules persistent, pale pinkish-green to yellowish-green, triangular-ovate, 5 – 7.5 × 3 – 6 mm, herbaceous, strongly keeled, abaxially densely villous-hirsute, margin minutely denticulate, apex aristate, arista ca. 3 mm long. Leaves alternate, oblique, held horizontally; petiole terete, crimson to brownish-pink tinged green, (2.5 –) 7 – 10 cm or longer, 2 – 3 mm diameter, densely white tomentose or villous, glabrescent; leaf blade asymmetric, oblique, widely ovate, (5 –) 7.5 – 16 × (3 –) 5 – 11 cm, broad side (1.5 –) 3 – 6.5 cm wide, basal lobes cordate, (1 –) 2.3 – 4.5 cm long, apex acuminate, margin denticulate with a line of pinkish-white hirsute; leaf chartaceous, succulent, adaxially bright green, olive green to malachite green, sometimes adorned with maroon to dark blueish-green narrow bands along all the veins, primary and secondary veins crimson; upper surface corrugated, moderately densely white hirsute, giving a wrinkled texture; abaxially pale green, densely white hirsute on all veins; venation basally ca. 8 palmate, midrib distinct, ca. 2 secondary veins on each side, other primary veins branching dichotomously or nearly so, tertiary veins reticulate; leaves of erect stem similar to terrestrial leaves but smaller. Inflorescence protandrous, terminal or axillary, bisexual, cymose panicle arising directly from rhizome or on a short stem, up to 3 orders of branching; peduncle crimson or brownish-pink tinged green, (3.5 –) 6 – 11 cm long, extending up to 23 cm in fruiting stage, sparsely to densely white tomentose; bracts deciduous, pale green to pale pinkish-yellow, ovate to elliptic, first pair 12 – 15 × 6 – 8 mm, abaxially tomentose-hirsute, margin denticulate, ciliate; bracts of upper inflorescence similar but smaller. Staminate flower: slightly pointing downward, pedicel white tinged dusky red towards base, 20 mm long, glabrous, tepals 4, white with pale grey veins, outer 2 ovate to widely ovate, 11 – 15 × 9 – 13 mm, abaxially sparsely hirsute, inner 2 obovate, 9 – 15 × 5.5 – 10 mm, glabrous; androecium actinomorphic, ca. 4 mm across; stamens golden yellow, 50 – 80, filaments fused into a column to 2 mm long; anthers obovate, ca. 1 mm long, 2 - locular, apex rounded, subequal or shorter than filaments. Pistillate flower: slightly pointing downward, pedicel white tinged dusky red towards base, 15 – 25 mm long, glabrous; tepals 5, white with pale greyish-white vein, outer 2 elliptic to widely elliptic, (10 –) 15 – 17 × (6 –) 10 – 13 mm, glabrous or sparsely hirsute abaxially; inner 3 elliptic to oblong-elliptic, (10 –) 17 – 20 × (5 –) 9 – 11 mm, glabrous; ovary pale green, trigonous-ellipsoid, ca. 10 mm long, 3 mm thick (wings excluded), scabrous-hirsute or hirsute; 3 - winged, wings unequal, pale green, crescent-shaped, glabrous or very sparsely hirsute, lateral wings narrower, 2 – 4.5 mm wide, abaxial wing 7 – 18 mm wide, margin entire; ovary 2 - locular, placenta bilamellate; styles 2, fused at base, yellow, ca. 3 mm long, stigmatic band U-shaped and spirally twisted. Capsule pedicel 2 – 3 cm long; ovary body trigonous-ellipsoid, 11 – 15 mm long, 4 – 6 mm thick (wings excluded); wings unequal, crescent-shaped, lateral wings ca. 4 mm wide, abaxial wing 15 – 22 mm wide. Additional specimens examined: — VIETNAM. Southern Vietnam, Binh Thuan province, Tanh Linh district, Duc Phu village, primary evergreen broad-leaved forest, around point 11 ° 21 ’ 48.5 ” N 107 ° 43 ’ 16.1 ” E, elevation of about 500 m a. s. l., 30 December 2024, D. M. Vu VDM 301224 (VNF).	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F83F8F6FFCCBFE8EFC3BFA0C.taxon	distribution	Distribution and ecology: — Begonia ducii is endemic to Binh Thuan province, southern Vietnam (Fig. 11). The new species usually grows in moist shady places near waterfalls, along streams and commonly on the slopes of stream valleys in moist places covered by evergreen broad-leaved forests.	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
03DF2916F83F8F6FFCCBFE8EFC3BFA0C.taxon	etymology	Etymology: — The specific epithet honors Mr. Vu Minh Duc, an plant enthusiast who provided material of this new species. Conservation status: — The area of occurrence and the number of mature individuals currently cannot be correctly estimated. More field surveys are needed for assessment of its true conservation status. According to the IUCN criteria (IUCN, 2024) it may be tentatively assessed at present as “ Data Deficient ” (DD). Notes: — Begonia ducii shares similarities with B. lamdongiana Lin et al. (2021: 82) and B. mangdenensis Hoang et al. (2021: 317), including hairy petioles, ovate leaf blades, staminate flowers with 4 tepals, and pistillate flowers with 5 tepals. However, B. ducii can be distinguished from both species by its densely corrugated upper leaf blade surface (vs. flat in B. lamdongiana and bullate in B. mangdenensis), moderately dense white hirsute hairs on the upper leaf surface (vs. sparsely minutely scabrous in B. lamdongiana and very sparsely puberulous in B. mangdenensis), and scabrous-hirsute ovary (vs. completely glabrous in other both species).	en	Nguyen, Cuong Huu, Bui, Huong Van, Le, Anh Tuan, Pham, Dien Van, Lin, Che Wei (2025): Five new species of Begonia (Begoniaceae) from Vietnam. Phytotaxa 698 (2): 82-100, DOI: 10.11646/phytotaxa.698.2.2, URL: https://doi.org/10.11646/phytotaxa.698.2.2
