Begonia shaoqingii D.K.Tian & J.Y.Zhou, 2024

Tian, Dai-Ke, Zhou, Jin-Ye, Xiao, Yan, Wu, Yan-Nong, Hu, Ren-Chuan, Dong, Xun & Guan, Shi-Kai, 2024, Three new species of Begonia (sect. Platycentrum) from South China, Phytotaxa 675 (2), pp. 147-157 : 151-154

2. Begonia shaoqingii D.K.Tian & J.Y.Zhou sp. nov. § Platycentrum (少卿ữåDz) ( Figs. 3 & 4 )

Type:— CHINA. Guangxi Zhuang Autonomous Region, Chongzuo city (崇左ḿ), Ningming county (Ṫẹ县), Aidan town (žŝḋ), Gongmu mountain (ȓ ḆƜ), soil or rock surface of wet and shady places along a creek near mountain top, 21°50'N, 107°1'E, alt. 1134 m, early flowering, 12 November 2023, Daike Tian, Renchuan Hu, Jinye Zhou, Xiangchun Lan TDK5539 (holotype CSH [ CSH 0204815], isotypes CSH [4]).

Diagnosis:— Begonia shaoqingii is mostly similar to B. rotundilimba Huang & Shui (1994) but differs mainly by its larger (4–20 × 3–15 cm vs. 7–9 × ca. 6.5 cm) leaf blade, later flowering (October–December vs. April), and 2-locular (vs. 3-locular) ovary. Also, it is similar to B. forrestii Irmscher (1939) in leaf morphology, but mainly differs by its habitat (rock surface vs. soil slope), abaxially sparsely (vs. densely) hirsute, white and rarely pink-white (vs. pink) flowers, and later flowering (October–December vs. April–May).

Perennial herb, rhizomatous, monoecious, 10–40 cm tall, erect stem absent. Rhizome creeping, unbranched to rarely branched, pink to reddish-brown, 5–15 cm long, 5–16 mm thick, internodes extremely short or inconspicuous. Stipules only seen at 1–3 apical nodes, green to reddish-brown, triangular, 3–13 × 3–9 mm, abaxially keeled, abaxially sparsely gray white or brown villous, awn at apex. Petioles reddish-brown or greenish-brown, gradually darkening downward to base, 5–30 cm long, 2–8 mm thick, terete, densely grayish-white villous when young, becoming sparsely brown villous when mature, hairs 2–8 mm long. Leaves 3–10 per plant, basal, alternate, subcoriaceous, thick, widely ovate, asymmetric, 4–20 × 3–15 cm, decurrent part 0.5–5 cm long; adaxially light green, glabrous or with very sparse grayish-white hairs when young, glabrous when mature, primary veins 6–9(–10), only main veins distinct, slightly concave; abaxially grayish-green, veins distinct, convex, densely covered with 2–3 mm long hairs on the veins, grayish-white when young and pale brown when mature, hairs longer on main veins and up to 5 mm long at base of main veins; margin subentire to occasionally with a few shallow teeth, margin grayish-white hairy when young; leaf bases slightly overlapped when young and often slightly overlapped to nearly valvate and rarely slightly separated when mature; apex acute or shortly caudate. Inflorescences dichasial cymes 1–2(–3) per plant, arising from 1–2 upper nodes of rhizome, 9–23 cm long, branched 1–2 times; peduncle upper portion green and basal portion greenish-brown or light reddish-brown (white flowered individuals), or occasionally entirely reddish-brown (light-pink flowered individuals), 7–18 cm long, 2–5 mm thick, sparsely gray-white villous, 3–11 flowers per inflorescence. Bracts caducous, light green (white flowered individuals) to light reddish-brown (light-pink flowered individuals), long ovate or ovate-triangular, basal bracts 6–10 × 4–9 mm, upper bracts 3–9 × 2–5 mm, abaxially villous, dorsal ridge conspicuous, apex with setiform trichome, margin sparsely gray-white villous. Staminate flower: pedicel glabrous to sparsely gray-white villous, 12–33 mm long, 1–1.5 mm thick; flower 29–39 mm long, 17–23 mm wide; tepals 4, usually white, partially white with pinkish tint, rarely pink, entire; outer 2 widely ovate to elliptical, 16–22 × 13–20 mm, abaxially glabrous or sparsely gray-white pubescent; inner 2 obovate-lanceolate to long obovate, glabrous, 7–11 × 3–5 mm; androecium yellow, bilaterally symmetric, 4–5 mm long, 5–6 mm wide, stamens 21–51, upward curved, filaments nearly free, 1.5–3 mm long, anthers 1–2 mm long, apex obtuse or rounded to slightly concave. Pistillate flower: pedicel glabrous to sparsely villous, 6–8 mm long, 1–1.5 mm thick, flower 25–29 mm long, 17–24 mm wide, tepals 5, usually white, occasionally pink, glabrous, entire; outer 2 broadly ovate or ovate, 10–16 × 5–17 mm; inner 3, gradually smaller inward, ovate, obovate, long obovate to subobovate-lanceolate, 5–10 × 3–6 mm; pistils 5–7 × 4–5 mm, styles 2, rarely 3, yellow, connate base 2–3 mm long, stigma spiraled nearly 1.5 revolutions; ovary light green, glabrous or occasionally sparsely villous, placentation axile, 2-locular, placentae 2 per locule. Fruits glabrous, 10–18 × 8–12 mm, pedicel glabrous, 13–20 mm long, 1–1.5 mm thick; unequally 3-winged, abaxial wing broadly falcate, 12–16 × 13–20 mm, sometimes sparsely villous along apex when young, lateral wings equal, narrowly falcate, 3–4 × 12–20 mm. Flowering Oct.–Dec., fruiting Nov.–Feb..

Distribution and Ecology: — The new species is currently known only in two places restricted to Guangxi of China ( Fig. 2 ), but it can be possibly found in northern Vietnam because one of populations is located at the China- Vietnam border. It grows on wet rock surface usually along creeks under forest.

Etymology: — The species is named after the name of Shaoqing Chen, a famous collector of plant specimens in China, who was the first person to collect the specimens of this species on 12 December 1934, Shaoqing Chen 3732 (IBSC). The Chinese name is given as “ 少卿ữåDz ”.

Additional specimens examined:— China, Guangxi: Chongzuo city (崇左ḿ), Mingjiang county (currently Ningming county ) (ẹȗ县, Κ为 Ṫẹ 县), Aidian town (žŝḋ), Gongmu mountain (ȓ ḆƜ), rock surface on the mountainside, white flower, 4 November 1935, Guangxi Provincial Museum 7558 ( IBSC) ; same mountain, rock surface on the mountain, white flower, 16 December 1935, Xiangri Liang 68135 ( IBK) ; same mountain, rock surface or crevices under the forest cover, 21°51'N, 107°1'E, alt. 1180 m, early flowering, 12 November 2023, Daike Tian, Renchuan Hu, Jinye Zhou, Xiangchun Lan, TDK5547 ( CSH). Qinzhou city, Qin county (currently Qinzhou city, Qinbei district) (ṻ县, Κ为ṻfflḿṻ北区), Guidong town (currently Guitai town ) (āfi乡, Κ为ā台ḋ), Bajiao mountain ( ĀĦƜ), alt. 300–400 m, valley, wet rock surface under forest, white flower, 12 December 1934, Shaoqing Chen 3732 ( IBSC) ; Qinbei district, Guitai town, Bazhaigou resort ( Ā Ṟṡạ 区), 22°6'N, 108°15'E, alt. 80–150 m, 27 June 2014, Daike Tian & Lizhi Tian TDK1910 ( CSH) ; Qinbei district, Guitai town, Nalue village ( Düť ), under coniferous and broad-leaved mixed forest, 22°4'N, 108°13'E, alt. 130 m, beginning of flowering, 10 December 2014, Hua Zhu, Zining Liang, Dan Liang, Yongyao Ling, Long Chen 450703141210013 LY ( GXMG) ; Bazhaigou resort of Guitai town , rock surface of wet and shady places along a creek, 22°6'N, 108°15'E, alt. 80 m, 4 June 2022, Jinye Zhou TDK4960 ( CSH) ; ibid., wet rock surface under forest along creek, alt. 80 m, without flower, 24 July 2023, Daike Tian, Jinye Zhou, Yannong Wu TDK5353 ( CSH) ; ibid., 22°5'N, 108°15'E, alt. 162 m, without flower, same date and collectors as before TDK5355 ( CSH) ; ibid., 22°6'N, 108°15'E, alt. 150 m, without flower, same date and collectors as before TDK5357 ( CSH) ; ibid., alt. 80 m, without flower, 13 November 2023, Daike Tian, Renchuan Hu, Jinye Zhou, Xiangchun Lan TDK5559 ( CSH). Chongzuo city, Pingxiang county (凭ṅḿ), cultivated plants introduced from Gongmu mountain of Ningming county , 29 November 2016, Daike Tian, Yi Tong, Lizhi Tian TDK3119 ( CSH). Shanghai city, Shanghai Chenshan Botanical Garden (上åIJƜDzń园), cultivated plants introduced from Gongmu mountain of Ningming county , Guangxi, 20 November 2021, Daike Tian & Songwei Wang TDK4955 ( CSH) .

Conservation status: — The new species is restricted to two locations within Guangxi. The extent of occurrence is about 150 km 2 (<5000 km 2) and the area of occupancy is less than 8 km 2 (<500 km 2). The total number of mature plants is less than 400 (<2500). Its occupancy area and the total number of mature plants are predicted to decline in the future due to climate change and collection for horticultural and medicinal purposes. Based on the current data, this species should be considered as Endangered (EN) (B1B2ab(iii,v)) following Guidelines for Using the IUCN Red List Categories and Criteria (IUCN Standards and Petitions Committee, 2024).

Figures

FIGURE 2. Distribution map of the three new species: ■Begonia liangguangensis, ▲ B. shaoqingii, ★ B. qinzhouensis, ● B. qinzhouensis and B. shaoqingii.

FIGURE 3. Habitat and morphology of B. shaoqingii D.K.Tian & J.Y.Zhou. A, B. Habitat; C. Habit; D, E. Cultivated plants in flower (taken on 28 December 2021); F. Adaxial leaf surface showing glabrous (upper) and sparsely hairy (lower) variants; G. Abaxial leaf surface showing dense hairs on veins; H. Hairs on petiole (upper) and peduncle (lower).

FIGURE 4. Morphology of B. shaoqingii D.K.Tian & J.Y.Zhou. A. Front and back views of inflorescence; B. Front and side views of staminate flowers showing tepals with different shapes and colors; C. Staminate flower showing glabrous (left) and hairy (right) outer tepals; D. Side view of androecium; E. Front (left) and side (right) views of pistillate flower; F. Stigmas; G, H. Bracts showing shape variation and hairs; I. Stipule; J. Cross-section of ovary; K. Side view of dried capsule.