Three new taxa of Begonia (sect. Coelocentrum, Begoniaceae) from limestone areas in Guangxi, China

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1 Botanical Studies (2006) 47: TAXONOMY Three new taxa of Begonia (sect. Coelocentrum, Begoniaceae) from limestone areas in Guangxi, China Ding FANG 1, Shin-Ming KU 2, 3, Yi-Gang WEI 4, De-Hai QIN 1, and Ching-I PENG 2,* 1 Guangxi Institute of Traditional Medical and Pharmaceutical Sciences, Guangxi Zhuangzu Autonomous Region, Nanning , China 2 Herbarium, Research Center for Biodiversity, Academia Sinica, Nangang, Taipei 115, Taiwan 3 Department of Life Sciences, National Cheng-Kung University, Tainan 701, Taiwan 4 Guangxi Institute of Botany, Guangxi Zhuangzu Autonomous Region and Academia Sinica, Guilin , China (Received July 18, 2005; Accepted December 3, 2005) ABSTRACT. Begonia ningmingensis, B. ningmingensis var. bella and B. retinervia, three new taxa of B. sect. Coelocentrum from the karst area in Guangxi Zhuangzu Autonomous Region, China, are described and illustrated. Notably, their leaves are adorned with white or pale maculation along all major veins. Begonia ningmingensis var. ningmingensis resembles B. morsei Irmsch., differing by having larger leaves with white maculation on the major veins and having larger staminate flowers. The maculation pattern in the leaves of B. morsei is sharply distinct: they are adorned with a broad, white ring between the center of the leaf and the margin. Begonia ningmingensis var. bella differs from the typical variety mainly by the suborbicular or reniform leaves with a rounded or obtuse apex (vs. broadly ovate or suborbicular with an acuminate, shortly acuminate or acute apex). Begonia retinervia is distinct chiefly by having thickly chartaceous leaves, the broadly trigonous-ovoid or obovoid ovary and fruit covered with crisp-villous hairs, and the ventral surface markedly convex, and in the much protruded abaxial wing. Keywords: Begonia morsei; Begonia ningmingensis; Begonia ningmingensis var. bella; Begonia retinervia; Begoniaceae; Begonia sect. Coelocentrum; China; Chromosome number; Guangxi; Limestone flora; New species; New variety. INTRODUCTION Begonia sect. Coelocentrum comprises about 18 species that are distributed mainly in southern China, but also in northern Vietnam (Shui et al, 2002). During the botanical inventories undertaken in recent years, many new species were discovered in China: Ku et al. (2004: B. curvicarpa and B. luochengensis); Liu et al. (2005: B. picturata); Peng et al. (2005a: B. fangii; 2005b: B. liuyanii), and Nguyen (2004) published B. phuthoensis from Vietnam. More recently, Shui and Chen (2005) added 11 new species and three new varieties for B. sect. Coelocentrum in China and proposed a new name, B. variegata for B. masoniana var. maculata S. K. Chen et al. from Vietnam. Begonia sect. Coelocentrum is therefore much more speciose than was previously believed. In this study we report two additional new species and an additional new variety, all with showy leaves, from the limestone areas in Guangxi, China. *Corresponding author: bopeng@sinica.edu.tw; Tel: ; Fax: New taxa 1. Begonia ningmingensis D. Fang, Y. G. Wei & C.-I Peng, sp. nov. TYPE: CHINA. Guangxi Zhuangzu Autonomous Region, Ningming Xian, Tingliang Xiang, Longrui Nature Protected Area, elev. ca. 140 m, broad-leaved forest, on limestone rock face in creek, shaded, wet, occasional, living collection, 2 Sep 2002, type specimens (in flower and fruit) pressed from plants cultivated in experimental greenhouse at Academia Sinica, 18 Oct 2004, Wai-Chao Leong, Yan Liu & Shin-Ming Ku 3410-A (holotype: HAST; isotypes: A, GXMI, IBK, MO, PE). 寧明秋海棠 Figures 1, 2 Begonia morsei auct. non Irmsch.: Ku, T. C., Fl. Reipubl. Popularis Sin. 52(1): 139, pl. 30: 3, , excl. typ. Begoniae morsei similis, sed a qua differt praecipue foliis majoribus, decoratis cum macula alba secundum venas majores, et floribus staminatis majoribus. Herbs monoecious; epipetric; perennial; rhizomatous. Rhizome 2-10 cm or more long, (2.5-)5-10(-16) mm thick, internodes (3-)5-10(-17) mm long, brown, reddish brown or greenish brown, villous near petiole bases and

2 98 Botanical Studies, Vol. 47, 2006 Figure 1. Begonia ningmingensis D. Fang, Y. G. Wei & C.-I Peng var. ningmingensis. A, Habit, leaf to right of inflorescence showing vestiture, leaves to left showing maculation. B, Leaf margin, adaxial surface; B', abaxial surface. C, Portion of leaf, adaxial surface; C', abaxial surface. D, D', Stipules. E, Bracts. F, Staminate flower. G, Stamen, lateral view; G', abaxial view; G", adaxial view. H, Carpellate flower, adaxial view; H', lateral view. I, Style and stigma, adaxial view; I', lateral view. J, Capsule. K: a-g, Serial cross sections of immature capsule. L. Seed. [D, L from Peng et al , HAST; others from Leong et al. 3410, HAST. All drawn from plants cultivated in the experimental greenhouse at Academia Sinica.]

3 FANG et al. Three new taxa in Begonia sect. Coelocentrum in China 99 Figure 2. Begonia ningmingensis D. Fang, Y. G. Wei & C.-I Peng var. ningmingensis. A, B, C, Habit and habitat. D, Cultivated plant at anthesis. E, Stipule. F, Leaf, cross section. G, Staminate flower, lateral view. H, Staminate flower, adaxial view. I, Carpellate fower, lateral view. J, Carpellate fower, adaxial view. K, Middle cross section of immature capsule. L, Style. M. Capsule. N, Seed SEM microphotograph. [A from Li HZ-047 (KUN); B from Leong et al (HAST); C, N from Peng et al (HAST); D-M from greenhouse-grown plants of Leong et al A (type collection, HAST).]

4 100 Botanical Studies, Vol. 47, 2006 leaf scars. Stipules eventually deciduous, triangular, narrowly triangular or ovate-triangular, (4-)5-10(-16) mm long, 4-10 mm wide, greenish or reddish hyaline, herbaceous or membranaceous, weakly keeled, with or without reddish nerves, with sparse minute subsessile brown glandular hairs on abaxial surface, midrib and base sparsely villous or glabrous, margin serrulate and ciliate or ciliolate, apex aristate, arista mm long, hairlike. Leaves 2-8, alternate, simple, asymmetric, unlobed or rarely very shallowly angular- lobed, broadly ovate or suborbicular, base cordate, margin denticulate and ciliolate, apex acuminate, shortly acuminate, or acute, rarely obtuse, (5.5-)10-15(-19) cm long (basal lobes included), (5-)7-12(-13) cm wide, upper surface green, dark green or dark brown with white maculation (these areas pale green abaxially) along major veins, sometimes only with some small white dots along major veins, very rarely without maculation, lower surface usually reddish, texture papery or thinly so, surface rugose or rugulose, adaxially pilose-setose or villous-setose (trichomes mm long, whitish hyaline or reddish, with a swollen base), abaxially shortly villous, particularly pronounced on veins; venation basally (6-)7(-8)-palmate, midrib distinct, veins pinnate along midrib, with 1-3 major lateral veins on each side, other primary veins branching dichotomously or nearly so, tertiary veins loosely reticulate and weakly percurrent, forming a divergence angle of to major veins, minor veins reticulate, all veins on abaxial surface prominently raised; petiole terete, (3-)8-15(-24) cm long, 2-4(-5) mm thick, brownish or brownish red, villous. Inflorescences axillary, 1-6 or more, arising directly from rhizome, dichasial cymes branched 2 or 3(or 4) times, with 5-21 flowers; staminate flowers 3-17, carpellate flowers 2-4; peduncle well developed, terete, erect or ascending, 4-21 cm long, mm thick, brownish, reddish brown or greenish, glabrous, subglabrous or very sparsely villous. Bracts caducous, ovate, oblong or ligulate, margin denticulate and ciliate or ciliolate (with a minute, glandular tip), apex obtuse or acute, 2-7 mm long, mm wide, greenish or brownish, membranous. Staminate flowers: pedicel 7-20 mm long, glabrous or with few minute subsessile glandular hairs, erect or ascending; tepals 4, outer 2 ovate, obovate, oblong or suborbicular, base rounded or slightly cordate, margin entire, eciliate, apex rounded, 12-20(-25) mm long, 12-16(-19) mm wide, pinkish, white or greenish white, with very sparse minute, subsessile, brown glandular hairs on outer surface, white or pinkish on inner surface; inner 2 tepals oblanceolate or narrowly obovate (rarely obovate), base cuneate, margin entire, eciliate, apex obtuse, 8-12(-18) mm long, 3-5 mm wide, white, glabrous; androecium zygomorphic, subglobose, stamens (25-)40-50, golf-club-shaped; filaments subequal, mm long, nearly free; anthers ± upwardly facing, locules 2, slightly compressed, oblongobovoid, apex of connective slightly emarginate, mm long, mm wide, yellow. Carpellate flowers: pedicel 5-12 mm long, horizontally spreading to pendent, bracteole absent or sometimes with 1 tiny bracteole; tepals 3, caducous, if persistent not thickened when fruiting, outer 2 tepals suborbicular or broadly obovate, margin entire, eciliate, mm long, 8-14 mm wide, white or pinkish, with sparse, minute, subsessile, brown glandular hairs on outer surface; inner tepal oblanceolate, obovate or narrowly so, base cuneate, apex obtuse or acute, 7-8 mm long, mm wide, white, glabrous; ovary trigonousellipsoid, 7-10 mm long, 4-5 mm thick (wings excluded), greenish white or reddish white, with or without very few glandular pilose trichomes ( mm long) and sparse, minute, subsessile, brown glandular hairs, 3-winged; wings unequal or subequal; lateral wings mm tall; abaxial wing crescent-shaped or nearly so, 2-4 mm tall, 6-9 mm wide; locule 1, placentation intruded parietal (axile at base); placentae 3, each 2-branched; styles 3, fused in lower 1/4-1/2, yellow, ca. 2 mm long, apically C-shaped; stigmatic band slightly spiraled. Capsule nodding, stipe 6-20 mm long, trigonous-ellipsoid, 9-10 mm long, 4-6 mm thick (wings excluded), greenish or reddish when fresh, apex with persistent styles; lateral wings mm tall; abaxial wing crescent-shaped or nearly so, 4-6 mm tall. Seeds numerous, brown, ellipsoid or broadly so, mm long, mm thick, chalazal end rounded, micropylar end obtuse or slightly constricted, outer periclinal walls of mature seeds concave; collar cells elongated, straight, nearly rectangular, cells in a ring, occupying 1/4-2/3 of seed length. Somatic chromosome number, 2n = 30 (Figure 3: A). Additional specimens examined. CHINA. Guangxi Zhuangzu Autonomous Region: Ningming Xian, Tingliang Xiang, Yuanjing Village, in dense broadleaved forests on limestone hill slope, elev. ca. 350 m, 10 Nov 1979, Nonggang Compl. Exped (GXMI); Ningming Xian, Tingliang Xiang, Longrui Nature Protected Area, elev. ca. 140 m, broadleaved forest, on limestone rock face in creek, shaded, wet, occasional, 2 Sep 2002, W. C. Leong, Y. Liu & S. M. Ku 3410 (HAST); Ningming Xian, Tingliang Xiang, Yuanjing Village, limestone hills, 30 Oct 2002, Y.-G. Wei 0223; Longzhou Xian (Longjin formerly), Paizong Xiang, Longxu, in dense forests on a limestone hill top, S. Q. Chen (IBK, IBSC); Longzhou Xian, Nonggang National Nature Reserve Headquarters, in a shaded, moist environment, 9 Nov 1985, Z. Y. Li, H. N. Qin & D. Z. Fu 005 (PE); Longzhou Xian, Shanglong Xiang, Nonggang National Nature Reserve, N, E, elev. ca. 180 m, mixed bamboo and broad-leaved forest, on limestone rock face, shaded, moist, occasional, 31 Aug 2002, W. C. Leong, Y. Liu & S. M. Ku 3404 (HAST); Longzhou Xian, Jinlong Zhen, Nonggang National Nature Reserve, N, E, broadleaved forest, in small valley, on limestone rock, shaded, moist, rare, 13 Sep 2003, W. C. Leong, J. Li, X. W. Li, W. H. Chen & Y. M. Shui 3632 (HAST); Longzhou Xian, Xiangshui Zhen, 3 Jun 2002, Li HZ-047 (KUN); Chongzuo Xian, Laituan Zhen, Longfeng Cun, White-headed Langur (Trachypithecus leucocephalus) Reserve, in sparse forests on limestone hill slope, elev. ca. 170 m, 23 Aug 2004, White-headed Langur Reserve

5 FANG et al. Three new taxa in Begonia sect. Coelocentrum in China 101 Figure 3. Mitotic chromosome spread of Begonia. A, Begonia ningmingensis var. ningmingensis (2n = 30); B, Begonia ningmingensis var. bella (2n = 30); C, Begonia retinervia (2n = 30).[A from W. C. Leong et al. 3410, B from C.-I Peng et al , C from C.-I Peng et al Vouchers at HAST.] Compl. Exped. B0445 (IBK); Chongzuo Shi, Laituan Zhen, Longfeng Cun, Dingna Tun, N, E, elev. ca. 175 m, on limestone rock face, N- or E-facing, occasional, 12 Mar 2005, C.-I Peng, S. M. Ku & H. Y. Chen (HAST); Chongzuo Shi, Laituan Zhen, Longfeng Cun, Dingna Tun, N, E, elev. ca. 175 m, on limestone rock face, shaded or semishaded, moist to dry, occasional, 12 Mar 2005, C.-I Peng, S. M. Ku, H. Y. Chen (HAST).. Ecology. On limestone hills in broadleaved forests. Distribution. Southwestern Guangxi, China (Figure 4). Etymology. The specific epithet is derived from the type locality, Ningming Xian (Ningming County). Phenology. Flowering from August to November; fruiting from October to January. Notes. Upon checking the specimen [Z. Y. Li et al. 005 (PE )] on which the line drawing of Begonia morsei Irmsch. in Ku (1999, pl. 30: 3, 4) was made, we determined that it is identifiable to B. ningmingensis var. ningmingensis. The expression of the leaf maculation of B. ningmingesis var. ningmingensis is variable (see Figure 2: A, B, C, D) and the leaves of plants in cultivation are often larger than those in the field. The maculation of the leaves may also be more pronounced in cultivated plants. Begonia ningmingensis var. ningmingensis resembles B. morsei Irmsch., differing mainly by having larger leaves with white maculation along the major veins and having larger staminate flowers. The maculation pattern of the leaves of B. morsei is sharply distinct: it consists of a broad white ring between the center of the leaf and the leaf margin (see Liu et al., 2005: Figure 7). Begonia morsei is known from only two specimens (syntypes) collected by H. B. Morse, without indication of the collection dates. Begonia morsei has not been recollected since the name was published by Irmscher (1939). Table 1 summarizes salient morphological features of B. ningmingensis var. ningmingensis, B. ningmingensis var. bella, B. retinervia and B. morsei. Figure 4. Distribution of Begonia ningmingensis var. ningmingensis ( ), B. ningmingensis var. bella ( ) and B. retinervia ( ) in Guangxi Zhuangzu Autonomous Region, China. 2. Begonia ningmingensis var. bella D. Fang, Y. G. Wei & C.-I Peng, var. nov. TYPE: China. Guangxi Zhuangzu Autonomous Region, Daxin Xian, Leiping Zhen, on shady limestone hills, 28 Oct 2002, Yi-Gang Wei 0221 (holotype: GXMI; isotypes: GXMI, IBK, PE). 麗葉秋海棠 Figures 5, 6 Differt a varietate typica Begoniae ningmingensis foliis suborbicularibus vel reniformibus apice rotundatis vel obtusis. Herbs monoecious; epipetric; perennial; rhizomatous. Rhizome 2-10 cm long, 3-5(-10) mm thick, internodes 3-7 mm long, brown or reddish brown, villous near petiole bases and leaf scars. Stipules eventually deciduous, triangular or ovate-triangular, 5-8 mm long, 2.5-7

6 102 Botanical Studies, Vol. 47, 2006 Figure 5. Begonia ningmingensis var. bella D. Fang, Y. G. Wei & C.-I Peng. A, Habit, upper two leaves showing maculation and others showing vestiture. B, Leaf, showing venation (left half), indumentum (upper right) and maculation (lower right). C, Portion of leaf, adaxial surface; C', cross section; C", abaxial surface. D, Stipule, abaxial surface; D', adaxial surface. E, Bract. F, Staminate flower. G, Androecium, showing filaments partly fused at base; G', showing nearly free filaments. H, Stamen, abaxial view; H', side view; H", adaxial view. I, Carpellate flower, adaxial view; I', lateral views. J, Style and stigmatic band, abaxial view; J', adaxial view. K: a-e, Serial cross sections of ovary. L, Capsule. M, Seeds. [All from Peng et al (HAST); B, M drawn from field material; others from plants cultivated in the experimental greenhouse at Academia Sinica.]

7 FANG et al. Three new taxa in Begonia sect. Coelocentrum in China 103 Figure 6. Begonia ningmingensis var. bella D. Fang, Y. G. Wei & C.-I Peng. A, B, Habit and habitat. C, Cultivated plant at anthesis. D, Leaf. E, Stipule. F, Staminate flower, outer tepal margin eciliate. G, Staminate flower, outer tepal margin ciliate. H, Carpellate flower. I, Middle cross section of ovary. J, Capsule, with glandular pilose trichomes. K, Nearly glabrous capsule. L, Seed SEM microphotograph. [All from Peng et al (HAST); A, B, K, L from field material; others from living plants cultivated in the experimental greenhouse at Academia Sinica.]

8 104 Botanical Studies, Vol. 47, 2006 mm wide, greenish or reddish hyaline, herbaceous or membranaceous, keeled or weakly keeled, abaxially with sparse minute subsessile brown glandular hairs and sparsely villous or not along keel, margin entire, eciliate, apex aristate, arista mm long, hair-like. Leaves 2-8, alternate, simple, asymmetric or pseudosymmetric, unlobed, suborbicular or reniform, base cordate, margin denticulate and ciliolate, apex rounded or obtuse, (2.8-)6-8.5(-13.5) cm long (basal lobes included), (2.5-)5-7.5(-12.5) cm wide, upper surface dark green, brown or dark brown, with white maculation (these areas pale green abaxially) along major veins, rarely only with some small white dots along major veins, lower surface reddish or red, texture papery, surface rugulose or rarely bullate, adaxially villous-setose or setosetomentose (trichomes mm long, whitish hyaline or reddish, with a swollen base), abaxially shortly villous, particularly on veins; venation basally 6-8-palmate, midrib distinct or sometimes indistinct, major veins branching dichotomously or nearly so, tertiary veins loosely reticulate and weakly percurrent, forming a divergence angle of to major veins, minor veins reticulate, all veins on abaxial surface prominently raised; petiole terete, (2-)6-10(-14) cm long, 2-3(-5) mm thick, brownish or brownish red, villous. Inflorescences axillary, 1-3, arising directly from the rhizome, dichasial cymes 1-3(-4) times branched, flowers 3-15; staminate flowers 2-10, carpellate flowers 1-4; peduncle well developed, terete, erect, 4-15 cm long, mm thick, brownish, reddish brown or greenish, glabrous or subglabrous. Bracts caducous, broadly ovate, obovate or oblong, margin denticulate and ciliate or ciliolate (with a minute glandular tip), apex obtuse or acute, mm long, mm wide, greenish or brownish, membranaceous. Staminate flowers: pedicel 1-2 cm long, glabrous or rarely with few minute subsessile glandular hairs, erect or ascending; tepals 4, outer 2 suborbicular to oblate, base rounded or slightly cordate, margin eciliate or ciliate, apex rounded, 8-13 mm long and wide, abaxially white, pinkish white or greenish white, with sparse minute subsessile brown glandular hairs, adaxially white or slightly pinkish, margin sometimes greenish; inner 2 tepals obovate or narrowly obovate, base cuneate, margin entire, eciliate, apex obtuse or rounded, 7-8 mm long, mm wide, white, glabrous; androecium zygomorphic, subglobose, stamens 20-35, golf-club-shaped; filaments subequal, mm long, nearly free or partly fused; anthers locules 2, slightly compressed, oblong-obovoid, connective apex slightly emarginate, mm long, mm wide, yellow. Carpellate flowers: pedicel 5-12 mm long, glabrous or with few minute subsessile glandular hairs, horizontal to pendent, bracteole absent; tepals 3, persistent; outer 2 tepals oblate or suborbicular, margin entire, eciliate or occasionally ciliolate below middle, 6-10 mm long, mm wide, abaxially white, pinkish or greenish, with sparse minute subsessile brown glandular hairs; inner tepal obovate or narrowly so, base cuneate, apex obtuse or rounded, 4-7 mm long, mm wide, white, glabrous; ovary trigonous-ellipsoid, mm long, 2-5 mm thick (wings excluded), greenish or reddish, glandular pilose or not (trichomes mm long) and with sparse minute subsessile brown glandular hairs; wings 3, unequal or subequal, lateral wings narrower, 2-3 mm tall, abaxial wing crescent shaped or nearly so, 3-5 mm tall, 4-6 mm wide; locule 1, placentation intruded parietal (axile at base), placentae 3, each 2-branched; styles 3, fused in lower 1/4 or nearly free, yellow, mm long, apically C-shaped, stigmatic band slightly twisted. Capsule nodding, stipe 6-12 mm long, greenish or reddish when fresh, 7-9 mm long, 4-6 mm thick (wings excluded), apex with persistent tepals and styles; lateral wings mm tall; abaxial wing crescent shaped or nearly so, mm tall. Seeds numerous, brown, ellipsoid or broadly so, mm long, mm thick, chalazal end rounded, micropylar end obtuse or slightly constricted, outer periclinal walls of mature seeds concave; collar cells elongated, straight, nearly rectangular, cells in a ring, occupying 1/3-2/3 of seed length. Somatic chromosome number, 2n = 30 (Figure 3: B). Additional specimens examined. CHINA. Guangxi Zhuangzu Autonomous Region: Daxin Xian, Leiping Zhen, ca. 250 m, in sparse forests on limestone hill slope, rare, D. Fang & L. Zeng 0415 (GXMI); Daxin Xian, Leiping Zhen, N, E, ca. 230 m, on W-facing limestone rocky slope, exposed, dry, 27 May 2005, C.-I Peng, W. C. Leong, S. M. Ku & Y. Liu (HAST); same field data but specimens (in flower and fruit) pressed from plants cultivated in experimental greenhouse at Academia Sinica, 6 Sep 2005, C.-I Peng, W. C. Leong, S. M. Ku & Y. Liu A (HAST). Ecology. On limestone hills, ca m altitude. Distribution. Southwestern Guangxi, China; very rare (Figure 4). Etymology. The epithet bella depicts the beautiful leaves with white maculation along the major veins on the upper surface with contrasting red lower surface. Phenology. Flowering from September to October; fruiting from November to December. Notes. Begonia ningmingensis var. bella is known only from one locality in southwestern Guangxi. We decided to recognize it as a variety of B. ningmingensis partly because it occurs near the distribution range of var. ningmingensis and partly because the two entities differ mainly by leaf shape and size (Table 1). Key to the varieties of B. ningmingensis 1a. Leaf broadly ovate or suborbicular with an acuminate, shortly acuminate or acute apex; stipules serrulate and ciliate or ciliolate at margin; tepals of carpellate flowers caducous, if persistent not thickened when fruiting...b. ningmingensis var. ningmingensis 1b. Leaf suborbicular or reniform with a rounded or obtuse apex; stipules entire, eciliate; tepals persistent and thickened in fruit...b. ningmingensis var. bella

9 FANG et al. Three new taxa in Begonia sect. Coelocentrum in China 105 Table 1. Comparison of Begonia ningmingensis var. ningmingensis, B. ningmingensis var. bella, B. retinervia and B. morsei. Stipules Leaf Shape Apex B. ningmingensis var. ningmingensis (Figures 1, 2) Margin serrulate and ciliate or ciliolate; weakly keeled Broadly ovate or suborbicular Acuminate, shortly acuminate or acute, rarely obtuse Size (cm) (5.5-)10-15(-19) (5-) 7-12(-13) Maculation pattern With white bands along major veins B. ningmingensis var. bella (Figures 5, 6) Margin entire, eciliate; keeled or weakly keeled B. retinervia (Figures 7, 8) Suborbicular or reniform Suborbicular Rounded, rarely obtuse (2.8-)6-8.5(-13.5) (2.5-) 5-7.5(-12.5) With white bands along major veins B. morsei (Liu et al., 2005: Figure 7) Margin entire, eciliate; Margin nearly entire, keeled or weakly keeled eciliate; distinctly keeled Obtuse, rounded, acute or shortly acuminate (4-)8-14(-25) (3.5-) 7-13(-22) With white bands along major veins Broadly ovate to suborbicular Shortly acuminate With a broad white ring between leaf center and margin Texture Papery or thinly so Papery Thickly papery Thinly papery Peduncle Glabrous or with a few pilose hairs Glabrous or with a few pilose hairs Glabrous or very sparsely villous Glabrous Tepals Size in staminate flowers (mm) Size in carpellate flowers (mm) Outer two 12-20(-25) 12-16(-19); inner two 8-12(-18) 3-5 Outer two ; inner one 7-8 Outer two ; Outer two ; inner two inner two Outer two ); inner one Color White or pinkish White, pinkish white or greenish white Persistence in arpellate flowers Androecium Caducous or persistent and not thickened when fruiting Subglobose; anthers more or less upwardly facing Persistent and slightly thickened when fruiting Subglobose; anthers slightly upwardly facing Filaments Nearly free Nearly free, occasionally fused at base into a short androphore (ca. 0.6 mm) Styles Fused in lower 1/3-1/2, rarely nearly free Capsule Shape Indumentum Abaxial wing shape Trigonous-ellipsoid, beak absent or indistinct Glabrous or sparsely pilose and with minute subsessile glandular hairs Crescent-shaped or nearly so, not curved Fused in lower 1/4 or nearly free Trigonous-ellipsoid, beak absent or indistinct Glabrous or pilose and with minute subsessile glandular hairs Crescent-shaped or nearly so; not curved Outer two ; inner one Pink to pinkish white Persistent and slightly thickened when fruiting More or less compressed; all anthers pointing in same direction and upwardly facing Nearly free Nearly free Broadly trigonous-ovoid or obovoid, adaxial side distinctly convex, apex sometimes with a short beak Crisp villous and with minute subsessile glandular hairs Obliquely triangular or ligulate, rarely obovateoblong; ± curved or subcucullate Outer two ; inner two Not available Unknown Unknown Subglobose; anthers slightly upwardly facing Fused at base into an androphore mm Unknown Height 4-6 mm mm (7-)10-15 mm 3-4 mm Trigonous-ellipsoid, beak absent or indistinct Only with minute subsessile glandular hairs Crescent-shaped or nearly so; not curved

10 106 Botanical Studies, Vol. 47, Begonia retinervia D. Fang, D. H. Qin & C.-I Peng, sp. nov. TYPE: CHINA. Guangxi Zhuangzu Autonomous Region, Du an Xian, Xiao Xiang, in sparse forests, on limestone hill slope, elev. ca. 200 m, 30 Sep 2004, Ding Fang & De-Hai Qin (holotype: GXMI). 突脈秋海棠 Figures 7, 8 Begoniae ningmingensis similis, sed a qua differt praecipue foliis crasse chartaceis, ovario et fructu late trigono-ovoideo vel obovoideo et crispo-villoso, et ala abaxiali multum protrudenti. Herbs monoecious; epipetric; perennial; rhizomatous. Rhizome 5-15 cm or more long, (3-)5-10(-16) mm thick, internodes (2-)5-10(-15) mm long, brown, reddish brown or greenish brown, sparsely villous. Stipules eventually deciduous, narrowly to broadly triangular, rarely ovateoblong, (3-)5-11 mm long, (3-)4-9 mm wide, greenish, herbaceous, keeled or weakly keeled, with sparse minute subsessile brown glandular hairs on abaxial surface, midrib sparsely villous or glabrous, margin entire, eciliate, apex aristate, arista 2-3 mm long, hair-like. Leaves 2-9, alternate, simple, asymmetric, unlobed or rarely very shallowly angular lobed, suborbicular, base cordate, margin denticulate and ciliolate, apex obtuse, rounded, acute or shortly acuminate, (4-)8-14(-25) cm long (basal lobes included), (3.5-) 7-13(-22) cm wide, adaxially dark green, brown or dark brown (abaxially reddish or red), with white maculation (pale green abaxially) along major veins, sometimes only with some small white dots along major veins, or pale green along veins, texture thickly papery, surface rugose, adaxially pilose-setose or villoussetose (trichomes mm long, whitish hyaline or reddish, with a swollen base), abaxially shortly villous, particularly on veins; venation basally (6-)7(-8)-palmate, midrib distinct, veins pinnate along midrib, with 1-3 major lateral veins on each side, other primary veins branching dichotomously or nearly so, tertiary veins loosely reticulate and percurrent, forming a divergence angle of to major veins, minor veins reticulate, all veins on abaxial surface prominently raised; petiole terete, (3-)5-13 cm long, 2-4(-6) mm thick, brownish or brownish red, villous. Inflorescences axillary, 1-5, dichasial cymes arising directly from rhizome, 2-4(-6) times-branched, flowers 5-26(-40); staminate flowers 3-20(-30), carpellate flowers 2-6(-10); peduncle well developed, taller than leaves, terete, erect initially, then ascending or pendent, 8-21 cm long, mm thick, brownish, reddish brown or greenish, sparsely villous or not and with sparse minute subsessile glandular hairs. Bracts caducous, recurved, broadly elliptic, oblong or obovate, margin serrulate and ciliate (with minute glandular tip), apex obtuse or nearly rounded, mm long, 1-7 mm wide, greenish or brownish, membranaceous, abaxially with minute subsessile glandular hairs. Staminate flowers: pedicel 6-25 mm long, erect or ascending, with few minute subsessile glandular hairs; tepals 4, outer 2 suborbicular, oblate or obovate, base rounded, margin eciliate or occasionally ciliate below middle, apex rounded, 6-16 mm long, 7-15 mm wide, pink or pinkish white, with very sparse minute subsessile brown glandular hairs abaxially; inner 2 tepals oblanceolate, obovate or narrowly so, base cuneate, margin entire, eciliate, apex obtuse, 6-14 long, mm wide, white or pinkish, glabrous; androecium zygomorphic, tilted, stamens 15-35, golf-club-shaped; filaments subequal, 1-2 mm long, base slightly fused; anthers upwardly facing, locules 2, slightly compressed, oblong-obovoid or narrowly so, apex of connective emarginate, mm long, mm wide, yellow. Carpellate flowers: pedicel 8-17 mm long, horizontal to pendent, with few minute subsessile glandular hairs, bracteole absent or rarely with 1 tiny bracteole; tepals 3, persistent and slightly thickened in fruit; outer 2 tepals suborbicular or oblate, margin entire, eciliate, 7-11 mm long, 9-13 mm wide, abaxially pinkish, with sparse minute subsessile brown glandular hairs; inner tepal narrowly obovate or obovate, base cuneate, apex obtuse, 5-10 mm long, mm wide, pinkish or white, glabrous; ovary broadly trigonous-ovoid or obovoid, ventral surface distinctly convex, 6-9 mm long, 4-5 mm thick (wings excluded), sometimes shortly beaked at apex, greenish white or reddish white, crisped villous (trichomes mm long, with a small glandular tip) and covered with sparse minute subsessile brown glandular hairs; wings 3, unequal; lateral wings narrower, curved along length of fruit body, mm tall; abaxial wing obliquely triangular or ligulate, rarely obovate-oblong, 3-8 mm tall, 4-6 mm wide; locule 1, placentation intruded parietal (axile at base); placentae 3, each 2-branched; styles 3, slightly tilted, fused at base, apically C-shaped; stigmatic band slightly spiraled. Capsule nodding, stipe 8-27 mm long, greenish or reddish when fresh, 7-11 mm long, 5-8 mm thick (wings excluded), apex with persistent styles and tepals; lateral wings mm tall; abaxial wing obliquely triangular or ligulate, rarely obovate-oblong, (7-)10-15 mm tall, 5-9(-11) mm wide. Seeds numerous, brown, ellipsoid or broadly so, mm long, mm thick, chalazal end rounded, micropylar end obtuse or slightly constricted, outer periclinal walls of mature seeds concave; collar cells elongated, straight, nearly rectangular, (8-)9-12 cells in a ring, occupying 1/4-2/3 of seed length. Somatic chromosome number, 2n = 30 (Figure 3: C). Additional specimens examined. CHINA. Guangxi Zhuangzu Autonomous Region: Du an Xian, Xiaao Xiang, Jiaba Cun, on shady and moist limestone hill slope, common, elev. ca. 550 m, 18 Apr 2002, D. Fang & D. H. Qin (GXMI); Du an Xian, Xiaao Xiang, Guanglong Cun, in a moist cave, elev. ca. 280 m, 11 Jun 2003, D. H. Qin & H. Z. Lin (GXMI); Longwan Xiang, on moist limestone hill slope, elev. ca. 200 m, 27 Mar 2003, D. H. Qin & H. Z. Lin (GXMI); same locality, 28 Aug 2003, D. Fang & D. H. Qin (GXMI); Du an Xian, at entrance of a limestone cave, N, E, elev. ca. 440 m scrubby vegetation, at foot of mountain, on rock face, semishaded, occasional, C.-I Peng, W. C. Leong, S. M. Ku & Y. Liu (HAST); Du an Xian, Xiaao Xiang, Jiaba Cun, 24

11 FANG et al. Three new taxa in Begonia sect. Coelocentrum in China 107 Figure 7. Begonia retinervia D. Fang, D. H. Qin & C.-I Peng. A, Habit. B, Leaf, cross section. C, Leaf margin, adaxial surface; C', abaxial surface. D, Stipule, abaxial surface; D', adaxial surface. E, Bract. F, Staminate flower. G, Stamen, lateral view; G', abaxial view; G", adaxial view. H, Carpellate flower, adaxial view; H', H", lateral views; H"', abaxial view. I, Style and stigmatic band, abaxial view; I', adaxial view. J, Capsule. K, Dehisced dry capsule. L: a-h, Serial cross sections of ovary. M, Seeds. [A-C, F-H', J from Peng et al (HAST); D from Peng et al (HAST); E, H"-I', L, M from Shui 9013; K from Qin & Lin (GXMI).]

12 108 Botanical Studies, Vol. 47, 2006 Figure 8. Begonia retinervia D. Fang, D. H. Qin & C.-I Peng. A, Habit and habitat. B, Cultivated plant at anthesis. C, Leaf. D, Leaf, cross section. E, Leaf margin, adaxial surface. F. Stipule. G, Staminate flower. H, Carpellate flower, lateral view. I, Carpellate flower, adaxial view. J, Cross section of ovary. K, Capsule. L, Seed SEM microphotograph. [A, F, K from Peng et al (HAST); B, D-I from Peng et al (HAST); C, J, L, from Shui 9013 (HAST).]

13 FANG et al. Three new taxa in Begonia sect. Coelocentrum in China N, E, 600 m elev., on limestone rocky slope, exposed, rare, 31 May 2004, specimens pressed from plants cultivated in experimental greenhouse at Academia Sinica, C.-I Peng, W. C. Leong, S. M. Ku & Y. Liu (HAST); same locality and date, N-facing limestone hill, in semi shady depression, specimens pressed from plants cultivated in experimental greenhouse at Academia Sinica, C.-I Peng, W. C. Leong, S. M. Ku & Y. Liu (HAST); exact locality unknown, 28 May 2002, Y. M. Shui 9013 (HAST). Ecology. Rocky limestone slopes and moist limestone caves, at m altitude. Distribution. North-central Guangxi, China; rare. (Figure 4). Phenology. Flowering from August to October; fruiting from November to March of the next year. Notes. Begonia retinervia resembles B. ningmingensis, differing mainly in having leaves thickly papery; ovary and capsule broadly trigonous-ovoid or obovoid and crisped villous, with a much-protruded abaxial wing and markedly convex adaxial side (Table 1). The distribution ranges of the two species are separated by ca. 200 km. Acknowledgements. We thank David E. Boufford (A/ GH) and Nicholas J. Turland (MO) for improving the manuscript; Hidetoshi Nagamasu (KYO) for the Latin diagnoses; Yan Liu (IBK), Yu-Min Shui (KUN), Wai-Chao Leong and Huan-Yu Chen (HAST) for accompanying and assisting us in the field; Hong-Zhe Li (KUN) for providing a handsome image (Figure 2: A) and the curators of GXMI, HAST, IBK, IBSC, K, KUN and PE for facilitating our examination of herbarium collections. This study was supported in part by grants from the National Science Council and Research Center for Biodiversity, Academia Sinica, Taiwan, to Ching-I Peng (HAST). Literature Cited Irmscher, E Die Begoniaceen Chinas und ihre Bedeutung fur die Frage der Formbildung in polymorphen Sippen. Mitt. Inst. Allg. Bot. Hamburg 10: Ku, T.C Begoniaceae. In T. C. Ku (ed.), Flora Reipublicae Popularis Sinicae, vol. 52(1). Science Press, Beijing, pp , Addenda, pp Ku, S.M., C.-I Peng, and Y. Liu Notes on Begonia (sect. Coelocentrum, Begoniaceae) from Guangxi, China, with the report of two new species. Bot. Bull. Acad. Sin. 45: Liu, Y., S.M. Ku, and C.-I Peng Begonia picturata (sect. Coelocentrum, Begoniaceae), a new species from limestone areas in Guangxi, China. Bot. Bull. Acad. Sin. 46: Nguyen, N.Q A new species of a peltate-leaved Begonia (Begoniaceae) from Vietnam. Novon 14: Peng, C.-I, Y.M. Shui, Y. Liu, and S.M. Ku. 2005a. Begonia fangii (sect. Coelocentrum, Begoniaceae), a new species from limestone areas in Guangxi, China. Bot. Bull. Acad. Sin. 46: Peng, C.-I, S.M. Ku, and W.C. Leong. 2005b. Begonia liuyanii (sect. Coelocentrum, Begoniaceae), a new species from limestone areas in Guangxi, China. Bot. Bull. Acad. Sin. 46: Shui, Y.M., C.-I Peng, and C.Y. Wu Synopsis of the Chinense species of Begonia (Begoniaceae), with a reappraisal of sectional delimitation. Bot. Bull. Acad. Sin. 43: Shui, Y.M. and W.H. Chen New data of sect. Coelocentrum (Begonia) in Begoniaceae. Acta Bot. Yunnan. 27(4):

14 110 Botanical Studies, Vol. 47, , 廣西壯族自治區中醫藥研究所中央研究院生物多樣性研究中心植物標本館國立成功大學生命科學系廣西壯族自治區中國科學院廣西植物研究所 本文發表中國廣西石灰岩地區秋海棠屬側膜組三個分類群 : 寧明秋海棠 (Begonia ningmingensis var. ningmingensis) 麗葉秋海棠 (B. ningmingensis var. bella) 和突脈秋海棠 (B. retinervia), 它們都有沿著葉脈分布的白色斑紋 本文提供了線繪圖與彩色照片以資辨識, 並報導它們的染色體數 ( 三者皆為 2n = 30) 寧明秋海棠與龍州秋海棠 (B. morsei) 相似, 但葉片沿脈分布白色斑紋 雄花較大 龍州秋海棠雖然體態形似寧明秋海棠, 但葉片上表面的斑紋型式為廣環帶狀, 明顯可以區別 麗葉秋海棠與寧明秋海棠的區別在於葉片較小 輪廓近圓形或腎形 先端圓或鈍 突脈秋海棠亦與寧明秋海棠相似, 但葉片質地較厚, 子房或果實 ( 含翅膀 ) 具捲曲長柔毛, 果實背翅較突出並向一側彎曲, 腹面顯著凸起 本文並將這四種相似的秋海棠之特徵予以列表比較 關鍵詞 : 龍州秋海棠 ; 寧明秋海棠 ; 麗葉秋海棠 ; 突脈秋海棠 ; 秋海棠科 ; 中國 ; 染色體數 ; 廣西 ; 石灰岩植物 ; 新種 ; 新變種 ; 側膜組