Bot. Bull. Acad. Sin. (2004) 45: 353-367

Ku et al. — Notes on Begonia from Guangxi, China, with the report of two new species

Notes on Begonia (sect. Coelocentrum, Begoniaceae) from Guangxi, China, with the report of two new species

Shin-Ming KU^1,2, Ching-I PENG^1,*, and Yan LIU³

¹Institute of Botany, Academia Sinica, Nankang, Taipei 115, Taiwan

²Department of Life Sciences, National Cheng-Kung University, Tainan 701, Taiwan

³Guangxi Institute of Botany, Guangxi Zhuangzu Autonomous Region and Academia Sinica, Guilin 541006, China

(Received July 1, 2003; Accepted September 30, 2004)

Abstract. Begonia curvicarpa and B. luochengensis, two new species of sect. Coelocentrum from the karst area in northern Guangxi Zhuangzu Autonomous Region, China are described and illustrated. Their somatic chromosome numbers, both 2n = 30, are reported. Begonia curvicarpa resembles B. porteri, from which it differs in having longer (1.5-5.5 cm vs. 0.8-1.7 cm) internodes on the rhizome, fewer hairs on upper leaf surface, and remarkably curved capsules. Begonia luochengensis is similar to B. luzhaiensis, but differs from the latter in having ovate (vs. orbicular to broadly ovate) leaves with a characteristic white band along midrib. Begonia yishanensis is treated as a synonym of B. porteri, and B. zhangii is treated as a synonym of B. daxinensis.

Keywords: Begoniaceae; Begonia cirrosa; Begonia curvicarpa; Begonia luochengensis; Begonia luzhaiensis; Begonia porteri; Begonia yishanensis; Begonia daxinensis; Begonia zhangii; China; Chromosome number; Guangxi; New species; sect. Coelocentrum.

Introduction

Begonia sect. Coelocentrum, characterized by a unilocular capsule with parietal placentation, was first delineated by Irmscher (1939) for four Chinese species (B. lanternaria Irmsch., B. morsei Irmsch., B. ornithophylla Irmsch. and B. porteri H. Lév. & Vaniot). All other sections of Chinese Begonia have axile placentation with two or more locules. In this paper Irmscher published Begonia filiformis Irmsch., a member of sect. Coelocentrum, but he erroneously assigned it to sect. Reichenhaimia (Shui et al., 2002). In Irmscher's 1951 paper two other new species of sect. Coelocentrum in China were added: B. obsolescens Irmsch. (transferred to sect. Diploclinium by Shui and Huang, 1999) and B. crispula Yu ex Irmsch. The latter is a later homonym of B. crispula Brade and a new name, B. cirrosa, was published for it by Smith and Wasshausen (1983). Irmscher (1959a, b) published yet another new species of sect. Coelocentrum, B. masoniana Irmsch. ex Ziesenh. It is a very handsome plant of great ornamental value, previously known as Begonia `Iron Cross' in the horticultural trade. The name B. masoniana Irmsch. was not validated until 1971 when Ziesenhenne made the appropriate typification.

More new species of Begonia sect. Coelocentrum became known in recent decades from China: B. umbraculifolia Y. Wan & B. N. Chang (Wan and Chang,

1987); B. pseudodryadis C. Y. Wu (Wu and Ku, 1995, as sect. Platycentrum; see Shui and Huang, 1999); B. biflora T. C. Ku, B. daxinensis T. C. Ku, B. guangxiensis C. Y. Wu, B. setuloso-peltata C. Y. Wu (Wu and Ku, 1997); B. obliquefolia S. H. Huang & Y. M. Shui (Shui and Huang, 1999); B. yishanensis Ku, B. luzhaiensis Ku (Ku, 1999); B. zhengyiana Y. M. Shui (Shui, 2002). In their synopsis of Chinese Begonia, Shui et al. (2002) listed 18 species for sect. Coelocentrum, including B. bonii Gagnep. and B. filiformis Irmsch. that were erroneously assigned to sect. Reichenheimia in the past.

Very recently, Fang et al. (2004) added one more species to sect. Coelocentrum: B. zhangii D. Fang & D. H. Qin. After careful examination of the type materials (GXMI, PE) and a field trip to recollect it, we conclude that it is synonymous with B. daxinensis T. C. Ku. Similarly, Begonia yishanensis T. C. Ku is hereby synonymized with B. porteri H. Lév. & Vaniot. During our intensive field surveys to Guangxi, China in recent years, we discovered two species of Begonia sect. Coelocentrum heretofore unknown to science, which are described below.

1. Begonia curvicarpa S. M. Ku, C.-I Peng & Y. Liu, sp. nov. —TYPE: China. Guangxi: Yongfu Xian, Baishou Zhen, Baishouyen, 19 Oct 2003, Yan Liu L0896 (holotype: IBK; isotypes: HAST, IBK). ÅsªG¬î®ü´Å

Figures 1, 2

Haec species affinis B. porteri H. Lév. & Vaniot, sed rhizomate internodiis longioribus (1.5-5.5 cm; 0.8-1.7 cm in B. porteri), et fructibus curvatis differt.

*Corresponding author. Tel: +886-2-2789-3821; Fax: +886-2-2789-1623; E-mail: bopeng@sinica.edu.tw

Botanical Bulletin of Academia Sinica, Vol. 45, 2004

Figure 1. Begonia curvicarpa S. M. Ku, C.-I Peng & Y. Liu. A, Habit; B, Leaf margin; C, Portion of leaf, adaxial surface, C', abaxial surface; D, Stipule, abaxial surface, D', adaxial surface; E, bract; F, Staminate flower, face view, F', lateral view; G, Stamen, dorsal view, G', ventral view; H & H', Carpellate flower, lateral view, H'', posterior view, H''', face view; I, Pistil; J, Style, dorsal view, J', ventral view; K, Fruit; L, Cross section of ovary, upper, L', middle, L'', basal; M, Seeds. (From W. C. Leong 3431; line drawing by S. M. Ku)

Ku et al. — Notes on Begonia from Guangxi, China, with the report of two new species

Figure 2. Begonia curvicarpa S. M. Ku, C.-I Peng & Y. Liu. A, Habit; B, Staminate flowers; C, Carpellate flower, face view; D, Fruit; E, Leaf blade; F, Carpellate flower, lateral view; G, Cross section of ovary; H, Seeds. (From Leong 3431 (HAST); photos by S. M. Ku)

Botanical Bulletin of Academia Sinica, Vol. 45, 2004

Plant monoecious; epipetric; perennial; rhizomatous, rooting at nodes. Rhizome succulent, creeping, elongate, somewhat zigzag, brown, sparsely hairy, 4-9 mm in diameter, internodes 1.5-5.5 cm long. Stipules often persistent, triangular, sparsely hairy along midrib, soon glabrescent on abaxial surface, thickly herbaceous, brownish to reddish brown, ca.10 mm long, 9 mm wide, apex aristate, margin entire. Leaves alternate, sparsely pilose on adaxial surface and villous on abaxial surface, densely hairy along major veins on abaxial surface, simple, asymmetric, obliquely broadly ovate to orbiculate, thin chartaceous, green above, green to reddish beneath, (4-) 6-10 (-19) cm long (basal lobes included), (3-) 4-9 (-12) cm wide, apex acute to acuminate, rarely obtuse, base cordate, margin denticulate or ciliate-dentate, sometimes crenate; venation basally 6-7-palmate, pinnate along the midrib, with 2-3(-4) major lateral veins on each side; petioles brown, terete, 7-12 (-17) cm long, 2-4 mm in diameter, slightly reflexed crisp-hairy. Inflorescences axillary, arising from the rhizome, cymose, 1-3 branched, flowers 3-5; peduncles well developed, brown to brownish-green, to 9-12 cm long, 2-3 mm in diameter, erect or ascending; pedicel reddish to brownish with many red flecks, ascending in staminate flowers, horizontal to pendent in carpellate flowers. Bracts caducous, oblong, elliptic to ovate, herbaceous, green to reddish, to 4-8 (-10) mm long, 3-4 (-6) mm wide, apex obtuse, margins ciliate-serrate. Tepals glabrous, margins entire. Staminate flowers: tepals 4, outer 2 white to pinkish on adaxial surface and pink on abaxial surface with reddish flecks, broadly ovate to ovate-orbiculate, base slightly cordate, apex rounded, 13-15 mm long, 15-17 mm wide, inner 2 white, oblanceolate, apex obtuse, ca. 12 mm long, 6 mm wide; androecium zygomorphic, stamens 35-40, golf-club shaped; filaments free, nearly equal in length, ca. 2 mm long; anthers 2-locular, slightly compressed, oblong, apex slightly emarginate, yellowish, ca. 1.2 mm long. Carpellate flowers:

tepals 3, outer two white to pinkish on adaxial surface and pink on abaxial surface with reddish flecks, occasionally white on both surfaces, broadly ovate to ovate-orbiculate, apex rounded, 14-17 mm long, 15-17 mm wide, inner one obtrullate to oblanceolate; ovary glabrous, pinkish and with many red flecks, somewhat curved, 3-winged; wings unequal; lateral wings much narrower, curved, thick, 3-4 mm high; abaxial wing elliptic or nearly triangular, 6-7 mm high, 7-8 mm wide; locule 1; placentation intruded parietal; placentae 3, branches 2-4 per placenta; styles 3, fused in the lower 1/3, yellow, 4-5 mm long, the top split into a rounded U-shape; stigmas U-form and somewhat spiraled. Fruit a dry capsule, nodding, greenish when fresh and brownish when dry, manifestly crooked, 11-14 mm long, ca. 8-9 mm wide (wings excluded), glabrous; lateral wings 4-5 mm high; abaxial wing 8-8.5 mm high, apex with persistent tepals and styles. Seeds many, brown, ellipsoid or broadly ellipsoid, 0.5-0.6 mm × 0.3-0.35 mm, chalazal end rounded, micropylar end somewhat constricted, outer periclinal walls collapsed in mature seeds; collar cells elongated, straight, nearly rectangular, 10-12 cells in a ring, occupying 1/2 to 1/3 of the seed length; anticlinal walls between the collar cells raised, straight, rarely slightly undulated; testa cell nearly isodiamentric-polygonal, mostly pentagonal and hexagonal, those adjacent to collar cells rarely slightly elongated. Somatic chromosome number, 2n = 30 (Figure 3A).

Paratypes. CHINA. Guangxi Zhuangzu Autonomous Region: Guilin Region, Youngfu Xian, Baishou Zhen, Baishouyen. 109°46' 50'' E, 25°10' 10'' N, elev. ca. 240 m, at base of limestone rock, semishaded, occasional. W. C. Leong 3431 (HAST), W. C. Leong 3707 (HAST), C.-I Peng 19850 (HAST); Rongan, Siding, Y. C. Wei and X. M. Chen 52990 (GXMI).

Ecology. Growing on limestone rocks or at entrance of semishady to shady, slightly moist caves.

Figure 3. Mitotic chromosome spreads of Begonia. A, Begonia curvicarpa (2n = 30); B, Begonia luochengensis (2n = 30). Scale bar = 5 µm. (A from W.C. Leong 3431, B from W.C. Leong 3419; both vouchers at HAST)

Ku et al. — Notes on Begonia from Guangxi, China, with the report of two new species

Distribution. Southern China.

Phenology. Flowering Aug to Nov; fruiting Oct to Dec.

Etymology: Named for the strikingly curved fruit.

Notes. Begonia curvicarpa is characterized by long-creeping rhizomes and crooked fruits. It resembles B. porteri H. Lév. & Vaniot, differing mainly in the much longer internodes of the rhizome, sparser pubescence on adaxial leaf surface and the remarkably curved fruits. However, its vestiture is similar to that of B. cirrosa L. B. Smith, which has a villous inflorescence and hirsute fruits. Table 1 summarizes the morphological differences between Begonia curvicarpa and four other somewhat similar species.

The leaves of B. curvicarpa are green on both surfaces or reddish-brown on upper surface and reddish to red beneath. Plants with reddish-brown leaves typically occur in exposed habitats, whereas the green-leaved individuals are usually found in shade.

2. Begonia luochengensis S. M. Ku, C.-I Peng & Y. Liu, sp. nov. —TYPE: China. Guangxi: Luocheng, Baotan Xiang, Cen Cun, Yan Liu L0899 (holotype: IBK; isotypes: HAST, IBK). ù«°¬î®ü´Å Figures 4, 5

Haec species affinis B. luzhaiensis T. C. Ku, sed foliis ovatis, costa albovittata differt.

Plant monoecious; epipetric; perennial; rhizomatous. Rhizome succulent, creeping, brown, sparsely hairy near the petiole base or scar, 8-20 mm in diameter, internodes 8-12 mm long. Stipules persistent, triangular-ovate, sparsely villous to glabrous on abaxial surface, herbaceous, greenish-hyaline, ca.7-10 mm long, 7-9 mm wide, apex aristate, margin ciliate-dentate or long-ciliate. Leaves alternate, tomentose on adaxial surface, hairs reddish, erect or slightly ascending, curved at tips; densely hairy along major veins and moderately along veinlets on abaxial surface; simple, asymmetric, obliquely ovate, chartaceous, with beautiful maculations on adaxial surface, often along the midrib,

Botanical Bulletin of Academia Sinica, Vol. 45, 2004

Figure 4. Begonia luochengensis S. M. Ku, C.-I Peng & Y. Liu. A, Habit, the leaf to the right of inflorescence showing vestiture, those to the left showing maculation; B, Portion of leaf, adaxial surface, B', abaxial surface; C, Leaf margin; D, Vestiture of leaf petiole; E, Stipule; F, Bracts; G, Staminate flower, face view; H, Stamen, ventral view, H', dorsal view, H'', lateral view; I, Carpellate flower, face view, I', lateral view; J, Pistil; K, Fruit; L-L'', Cross sections of ovary; M, Seed. (From W. C. Leong 3419 (HAST); line drawing by S. M. Ku)

Ku et al. — Notes on Begonia from Guangxi, China, with the report of two new species

Figure 5. Begonia luochengensis S. M. Ku, C.-I Peng & Y. Liu. A, Habit; B, Fruit with persistent tepals; C, Staminate flower buds; D, Staminate flower; E, Leaf blade; F, Seeds. (From W. C. Leong 3419; photos by S. M. Ku)

Botanical Bulletin of Academia Sinica, Vol. 45, 2004

forming a white zone (often composed of many little white spots), pale green near the major veins and major lateral veins, dark brownish to purplish red between major veins and major lateral veins, reddish on abaxial surface, (10-) 15-20 (-25) cm long (including basal lobes), (5-) 7-12 (-18) cm wide, apex acuminate to caudate, base cordate, margin denticulate or ciliate-dentate; venation basally 7-palmate, pinnate along the midrib, with 3-5 major lateral veins on each side; petioles brown, terete, 8-20 (-30, when cultivated in pot) cm long, 5-7 mm in diameter, villous, hairs whitish, dense, straight to curly, somewhat reflexed. Inflorescences axillary, arising directly from the rhizome, cymose, 2-4-branched, flowers 7-14; peduncles well developed, brownish, 8-22 cm long, 3-4 mm in diameter, nearly glabrous; pedicel reddish, ascending in staminate flowers and horizontal to pendant in carpellate flowers. Bracts caducous, oblong, herbaceous, green to reddish, 6-9 mm long, 4-5 mm wide, apex acute to obtuse, margin sparsely ciliate-serrate. Tepals glabrous, margin entire. Staminate flowers: tepals 4, outer 2 pinkish on adaxial surface and reddish on abaxial surface, ovate-orbiculate, base slightly cordate, apex rounded, 11-12 mm long, 12-13 mm wide, inner 2 pinkish, broadly oblanceolate, apex obtuse, ca. 12 mm long, ca 6.5 mm wide; androecium zygomorphic, stamens 20-27, golf-club shaped; filaments free, nearly equal in length, ca. 1.6 mm long; anthers 2-locular, slightly compressed, oblong, apex slightly emarginate, yellowish, ca. 1.4 mm long. Carpellate flowers: tepals 3, outer 2 pinkish on adaxial surface and pink on abaxial surface, broadly ovate-orbiculate, apex rounded, 13-14 mm long, 15-17 mm wide, inner one obovate, apex rounded; ovary glabrous, pinkish at anthesis, 3-winged; wings unequal; lateral wings much narrower, 3-4 mm high; abaxial wing oblong to nearly triangular, ca. 6 mm high, 8-9 mm wide; locule 1; placentation intruded parietal; placentae 3, each 2 (-4) branched; styles 3, nearly free (slightly fused at base), yellow, ca. 4 mm long, the summit U-shaped; stigmas U-form or nearly reniform. Fruits a dehiscent capsule, nodding, greenish to reddish when fresh and brownish when dry, 11-17 mm long, ca. 6-7 mm wide (wings excluded); lateral wings 3-4 mm high; abaxial wing to 10-12.5 mm high, apex with persistent tepals and styles. Seeds many, brown, ellipsoid or broadly ellipsoid, the chalazal end rounded, the micropylar end slightly constricted or not, outer periclinal walls collapsed in mature seeds; collar cells elongated, straight, nearly rectangular, 10-12 cells in a ring, occupying 1/2 to 1/3 of the seed length; anticlinal walls between the collar cells raised, straight, rarely slightly undulate; testa cell nearly isodiamentric-polygonal, mostly pentagonal and hexagonal, those adjacent to collar cells rarely slightly elongated. Somatic chromosome number, 2n = 30. (Figure 3B)

Paratype. CHINA. Guangxi Zhuangzu Autonomous Region: Hechi Diqu, Luocheng Mulaozu Zizhixian, Huaiqun Zhen, 180°34' 12'' E, 24°50' 35''N; elev. ca. 250 m, W. C. Leong 3419 (HAST).

Ecology. Growing on semishaded, dry or slightly moist limestone hills.

Distribution. Southern China.

Phenology. Flowering Aug to Nov; fruiting Sep to Dec.

Etymology. Named for the Luocheng minority county where it was collected.

Notes. Begonia luochengensis is characterized by ovate leaves that are densely pubescent and with a remarkable white band along the midrib on upper surfaces. It resembles B. luzhaiensis T. C. Ku, which, however, has broadly ovate to orbiculate leaves that are usually shallowly angularly lobed. In addition, the leaves of B. luzhaiensis do not form a white band along the midrib. It is also similar to B. porteri H. Lév. & Vaniot in the vestiture of the leaf upper surface, but that species is smaller and has much slenderer rhizome than B. luochengensis. For comparison of characteristics see Table 1.

3. Begonia porteri H. Lév. & Vaniot, Feddes Repert. Spec. Nov. Regni Veg. 9: 20. 1910 et Fl. Kouy-Tcheou 46. 1914; Gagnep. in Lecomte, Fl. Gen. Indo-Chine 2: 1108. 1921; Irmscher, Mitt. Inst. Allg. Bot. Hamburg 10: 554. 1939; Lauener, Notes Roy. Bot. Gard. Edinburgh 31(3): 435. 1972; Ku, Fl. Reipubl. Popul. Sin. 52(1): 142, pl. 30: 1-2. 1999. ù¨l¬î®ü´Å Figures 6-8

Begonia bellii H. Lév., Fl. Kouy-Tcheou 45. 1914, "belli"; Irmscher, Mitt. Inst. Allg. Bot. Hamburg 10: 54. 1939.

Begonia yishanensis T. C. Ku, Acta Phytotax. Sin. 37(3): 285, pl. 1. figs. 3, 4. 1999 et Fl. Reipubl. Popul. Sin. 52(1): 136. 1999. syn. nov.

Specimens examined. CHINA. Guizhou ("Kouy-Tcheou"): Lo-Fou, Oct 1908, J. Cavalerie 3607 (holotype: E; isotype: UPS).—Guangxi: Yishan, Gulong, 12 Dec 1987, Exped. Yishan 16426 (holotype of B. yishanensis: GXEM; isotype of B. yishanensis: GXMI); Guangxi Zhuangzu Autonomous Region (exact locality unknown), 28 May 2002, Y. M. Shui 9009c (HAST); Guangxi Zhuangzu Autonomous Region: Luocheng Mulaozu Zizhixian, Qiaoshan Xiang, 24°52'40''N, 108°44' 14''E, 160 m alt., NW-facing limestone slope, 1 Jun 2004, C.-I Peng 19840 (HAST).

Ecology. Growing on semishaded, slightly moist limestones and caves.

Distribution. Southern China.

Phenology. Flowering Aug - Nov; fruiting Sep - Dec.

Notes. We examined type materials of B. porteri at E (holotype) and UPS (isotype), and found that although many leaves are ovate, some are nearly orbiculate (Figure 7B, F) and cannot be distinguished from B. yishanensis. The leaf vestiture of B. porteri and B. yishanensis also cannot be distinguished from each other. We agree with the annotation made by Yu-Min Shui on the holotype specimen of B. yishanensis (Figure 8A) that the two taxa are conspecific.

4. Begonia daxinensis T. C. Ku, Acta Phytotax. Sin. 35(1): 45, fig. 26. 1997. ¤j·s¬î®ü´Å Figures 9, 10

Begonia zhangii D. Fang & D. H. Qin, Acta Phytotax. Sin. 42(2): 170, fig. 1. 2004. syn. nov.

Ku et al. — Notes on Begonia from Guangxi, China, with the report of two new species

Figure 6. Begonia porteri H. Lév. & Vaniot. A, Habit: plant with flower buds; B, Habit: plant with dried capsules from previous season; C, Cultivated plant at anthesis; D, Staminate flower; E, Carpellate flower, face view; F, Carpellate flower, lateral view; G, Dry capsule. Scale bar = 5 cm in C; 5 mm in D-G. (All but F from C.-I Peng 19840, F from Y. M. Shui 9009c; photos A, B by C.-I Peng, C by M. L. Weng, D-G by S. M. Ku)

Botanical Bulletin of Academia Sinica, Vol. 45, 2004

Figure 7. Types specimens of Begonia porteri H. Lév. & Vaniot. A-E. Holotype at Royal Botanic Garden, Edinburgh (E): A, Specimen; B, A leaf in fragment envelope; C, Leaf margin and vesture; D, Fruit and abaxial side of leaf; E, Rhizome; F-H, Isotype at Herbarium of Uppsala Botanical Museum, Uppsala University (UPS): F, Specimen; G, Fruit with persistent tepals; H, Fruiting specimen. (Kouy-Tcheou: Lo-Fou, Cavalerie 3607) (Photos A, B, C, E by S. M. Ku, D; F-H by C.-I Peng)

Ku et al. — Notes on Begonia from Guangxi, China, with the report of two new species

Figure 8. Type specimens of Begonia yishanensis T. C. Ku. A-D: A, Holotype at GXEM; B, Leaf; C, Close-up image of the type; D, Materials in fragment envelope; E-F, Isotype at GXMI. (Guangxi: Yishan, Gulong, Exped. Yishan 16426). (Photos A-D by C.-I Peng; E-F by S. M. Ku)

Botanical Bulletin of Academia Sinica, Vol. 45, 2004

Figure 9. Begonia daxinensis T. C. Ku. A, B, Habit; C, Leaf, abaxial surface; D, Staminate flower; E, Fruit. Scale bars: D = 1 cm, E = 5 mm. (From C.-I Peng 19695; photos A-C by C.-I Peng, D-E by S. M. Ku)

Ku et al. — Notes on Begonia from Guangxi, China, with the report of two new species

Figure 10. A-B. Holotype of Begonia daxinensis T. C. Ku. (H. N.Qin 17, PE): A, Specimen; B, Rhizome; C-D, Holotype of B. zhangii D. Fang & D. H. Qin, (C. L. Zhang et al. 033, GXMI); C, Specimen; D, Inflorescence; E, Paratype of B. zhangii D. Fang & D. H. Qin, C. L. Zhang et al. 73310 (GXMI). (Photos by S. M. Ku)

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Literature Cited

Fang, D., Y.G. Wei, and D.H. Qin. 2004. Four new species of Begonia L. (Begoniaceae) from Guangxi, China. Acta Phytotax. Sin. 42(2): 170-179.

Irmscher, E. 1939. Die Begoniaceen Chinas und ihre Bedeutung für die Frage der Formbildung in polymorphen Sippen. Mitt. Inst. Allg. Bot. Hamburg 10: 431-557.

Irmscher, E. 1951. Some New Chinese Species of Begonia. Notes Roy. Bot. Gard. Edinburgh 21(1): 35-45.

Irmscher, E. 1959a. Begonia masoniana Irmscher. Begonian 26(9): 202-203.

Irmscher, E. 1959b. Begonia masoniana Irmscher_ Latin description. Begonian 26(10): 231.

Ku, T.C. 1999. Begoniaceae. In T.C. Ku (ed.), Flora Reipublicae Popularis Sinicae vol. 52(1). Science Press, Beijing, pp. 126-269, Addenda, pp. 401-402.

Shui, Y.M. and S.H. Huang. 1999. Notes on the genus Begonia from Yunnan. Acta Bot. Yunnan. 21(1): 11-23.

Shui, Y.M. 2002. A new species of Begonia (Begoniaceae) from SE Yunnan, China. Acta Phytotax. Sin. 40(4): 374-376.

Shui, Y.M., C.-I. Peng, and C.Y. Wu. 2002. Synopsis of the Chinese species of Begonia (Begoniaceae), with a reappraisal of sectional delimitation. Bot. Bull. Acad. Sin. 43: 313-327.

Smith, L.B. and D.C. Wasshausen. 1983. Notes on Begoniaceae—I. Phytologia 52(7): 441-451.

Wan, Y. and B.N. Chang. 1987. A new species of the genus Begonia from Guangxi. Acta Phytotax. Sin. 25(4): 322-323.

Wu, C.Y. and T.C. Ku. 1995. New taxa of the Begonia L. (Begoniaceae) from China. Acta Phytotax. Sin. 33(3): 251-280.

Wu, C.Y. and T.C. Ku. 1997. New taxa of the Begonia L. (Begoniaceae) from China (Cont.). Acta Phytotax. Sin. 35(1): 43-56.

Ziesenhenne, R. 1971. Typification of Begonia masoniana Irmscher. Begonian 38 (3): 52.

Specimens examined. CHINA. Guangxi: Daxin, in shady places of limestone hills, 4 Apr 1981, H. N. Qin 17 (PE, holotype); Longan, Dujie, in forests, limestone hill, 29 Mar 1984, C. L. Zhang et al. 033 (GXMI, holotype of B. zhangii), C. L. Zhang et al. 042 (GXMI, paratype of B. zhangii); same locality, alt. ca. 300 m, 4 Apr 2002, C. L. Zhang et al. 73310 (GXMI, IBK, PE, paratypes of B. zhangii); locality unknown, 29 Mar 1984, X. H. Lu 12317 (GXMG); Guangxi Zhuangzu Autonomous Region: Chungzuo Shi, Tiandeng Xian, Bahe Xiang, 1 km S of Duoda Cun, 580 m, 106°47' 34''E, 23°10' 23''N, at base of a steep limestone hill, on N-facing rocky slope face or at base of limestone rocks, shaded, 25 May 2004, C.-I Peng 19695 (HAST).

Ecology. Growing on slightly moist semishaded, limestone hillside.

Distribution. Southern China.

Phenology. Flowering Mar - May; fruiting Mar - May.

Notes. Begonia daxinensis bears a superficial resemblance with B. rex Putz. (sect. Platycentrum), particularly in leaf shape and maculation. Begonia rex Putz., however, has axile placentation with 2 locules and carpellate flowers with 5 tepals (vs. parietal placentation with 1-locule and 3 tepals in carpellate flowers). Morphological distinction between B. zhangii D. Fang & D. H. Qin and B. daxinensis T.C. Ku are simply not available. We are thus synonymizing B. zhangii with Begonia daxinensis.

Acknowledgments. This study was supported in part by a research grant from National Science Council and Academia Sinica, Taiwan. We thank Prof. Ding Fang (GXMI), curators of GXMG, GXMI, HAST, IBK, PE, UPS for facilitating our specimen examination, Prof. Ding Fang (GXMI), Dr. Yu-Min Shui (KUN) and Mr. Wai-Chao Leong (HAST) for field assistance, and Dr. Dan H. Nicolson (US) for improving the manuscript.

Ku et al. — Notes on Begonia from Guangxi, China, with the report of two new species