Begonia ehuangzhangensis Q.L. Ding, W.Y. Zhao & W.B. Liao, 2018

Ding, Qiao-Ling, Zhao, Wan-Yi, Yin, Qian-Yi, Ye, Hua-Gu, Song, Han-Zhang & Liao, Wen-Bo, 2018, Begonia ehuangzhangensis (sect. Diploclinium, Begoniaceae), a new species from Guangdong, China, Phytotaxa 381 (1), pp. 107-115 : 107-109

Begonia ehuangzhangensis Q.L. Ding, W.Y. Zhao & W.B. Liao , sp. nov. ( Figs. 2 & 3 ).

Diagnosis: — Begonia ehuangzhangensis is most similar to B. fimbristipula Hance (1883: 202) in tuber shape, placentation type, and leaf number, but significantly differs by petiole and blade glabrous (vs. hairy), female flower 2 tepals (vs. 3 tepals), and later flowering period (August vs. May). Begonia ehuangzhangensis also resembles B.

rongjiangensis T.C. Ku in Wu & Ku (1995: 279) but distinguished from the latter in having glabrous outer tepals of male flower, glabrous ovary, glabrous and persistent bracts, U-shaped stigmas, and solitary leaf per tuber. Comparison of the above three species is provided in Table 1.

Type:— CHINA. Guangdong:Yangchun City, Bajia Town,Ehuangzhang Nature Reserve,elev. 704m, 21°52’26.88” N, 111°25’20.51” E, on wet, mossy rock slope at sides of valley, along the stream, 5 August 2017, H. G. Ye, W. Y. Zhao, Z. C. Liu, YC-2017-13 (Holotype SYS!, isotypes SYS!, IBSC!).

Description:— Herb monoecious, deciduous perennial, epipetreous with tubers; tuber irregular globose, 6–8 mm in diameter, single or two connected. Leaf solitary per tuber, basal; stipule caducous; petiole green or slightly reddish, 3.5–8.5 cm long, 1.5–3 mm in diameter, glabrous; blade slightly oblique, ovate, 4–12 × 2.5–6.5 cm, chartaceous, glabrous, adaxial surface green, abaxial surface reddish, base slightly cordate, margin biserrate, apex acute or cuspidate; venation palmate, green, usually 7-veined, raised on abaxial surface. Inflorescence 1 or 2, arising from the tuber, dichasium, 4.5–12.5 cm tall, glabrous; peduncles green or reddish, 4.5–9 cm long and 1–3 mm in diameter; bracts reddish, triangular, margin serrate, ca. 2 × 1 mm, glabrous, persistent, 1 or 2-paired at the base of each peduncle; bracteoles reddish, tridentate or slight tridentate at apex, margin sparsely glandular ciliate, remotely serrulate at middle and base, ca. 3 × 1 mm, paired at each pedicel node. Staminate flower: pedicel glabrous, 1–2.2 cm long; tepals 4, pale-pink, glabrous, outer 2 ovate to broad ovate, 4–6 × 3–5 mm, inner 2 narrowly obovate, 4–6 × 1–1.5 mm; filaments fused to about 1 mm at base; anther hemispherical, yellow, about 0.5 mm long. Pistillate flower: pedicel glabrous, 1–1.5 cm long; tepals 2, pale-pink, glabrous, broadly obovate, 3–3.5 × 3.5–4 mm; ovary oblong, reddish, glabrous; placentation axile, bilamellated; styles 3, fused at base; stigma U-shaped, papillate. Capsule nodding, ca. 8 × 7 mm, unequally 3-winged, abaxial wing oblate-triangular, ca. 4 × 5 mm, apex acute, lateral wings smaller, lunate, about 1 mm in width; seeds many, brown, ellipsoid.

Additional specimens examined (paratypes):— CHINA. Guangdong Province, Yangchun County, Bajia Town, Ehuangzhang Nature Reserve , elev. 700 m, 21°52’26” N, 111°25’20” E, 5 August 2017, H. G. Ye, W. Y. Zhao, Z. C. Liu,YC-2017-40 ( SYS!) ; ibid., 9 November 2017, W. Y. Zhao, F. Ye, J. W. Pan, YC-2017-49 ( SYS!) ; ibid., elev. 720 m, 21°51’47” N, 111°25’29” E, 5 August 2018, Q. L. Ding, W. Y. Zhao, Q. Y. Yin, Y. R. Liu, YC-2018-16 ( SYS!) .

Distribution and habit:—The new species is currently known only from the Ehuangzhang Nature Reserve ( Fig. 1 ) and grows on moist rocky slope at sides of valley, along the stream in broad-leaved mixed forests at about 700 m in elevation.

Phenology:—Flowering August to September, fruiting September to October.

Etymology:—The specific epithet is derived from the type locality, Ehuangzhang Nature Reserve of Guangdong Province, China.Although several endemic species from Ehuangzhang Nature Reserve were named after the Yangchun city ( Kiu 1995, Ye et al. 2003, 2006, Wang et al. 2005), the authors wish to emphasize the unique geographical features of Ehuangzhang Nature Reserve, thus to name this new species after this nature reserve.

Figures

FIGURE 1. Distribution of Begonia ehuangzhangensis (▲) in Guangdong province of China.

FIGURE 2. Begonia ehuangzhangensis. A. Habit; B. Staminate flower, face view; B’. Staminate flower, side view; C. Carpellate flower, face view; C’. Carpellate flower, side view; D, D’, D’’. Style and stigma; E, E’. Stamen; F. Capsule; G. Cross section of ovary; H. Bract; I, Bracteole.

FIGURE 3. Begonia ehuangzhangensis. A. Habit and habitat; B–C. Inflorescence; D–E. Staminate flower; F–G. Carpellate flower; H. Androecium; I. Styles and stigma; J. Placentation; K. Bracts; L. Bracteole; M. Seed; N. Infructescence; O. Tubers; P. Abaxial surface of leaf; Q. Adaxial leaf surface and leaf margin.A–P are from the wild materials; Q is from the herbarium specimen.