Begonia ufoides C.-I Peng,Y.H. Qin & C.W. Lin, 2017

1. Begonia ufoides C.-I Peng,Y.H. Qin & C.W. Lin View in CoL , sp. nov. ( Figures 1 View FIGURE 1 , 2 View FIGURE 2 ) ḍğkằǟ

Sect. Coelocentrum

Type:–– CHINA. Guangxi Zhuangzu Autonomous Region. Nanning City. Mashan Xian , elev. ca. 350 m. Mixed bamboo plantation and broadleaf forest on limestone mountain slope. Herb at early anthesis, on shaded, moist, concaved limestone rock face, very rare. 13 June 2014, Ching-I Peng 24356, with Chien-I Huang and Wei-Bin Xu (holotype IBK ; isotype HAST )

Monoecious rhizomatous herb. Rhizome creeping, to 10 cm or longer, 0.6−1 cm thick, internodes congested, less than 0.5 cm, glabrous. Stipules persistent, reddish, widely triangular-ovate, 0.5–0.8 cm long and wide, herbaceous, strongly keeled, glabrous, margin ciliate on the lower half, apex aristate, arista ca. 0.3 cm long. Leaves peltate, petiole terete, olive green, petiole attachment displaced to one side, 7−11 cm long, 0.3−0.5 cm thick, densely pilose; blade oblate or suborbicular, coriacellate to coriaceous, succulent, 4.5−9 cm long, 4–8.8 cm wide, broad side 3–5.7 cm wide, base rounded or very slightly retuse, apex rounded, margin obscurely denticulate and puberulous, slightly recurved; adaxially dark green, with narrowly emerald zones along primary and secondary veins, very sparsely minutely scabrescent; abaxially crimson to magenta, densely puberous on all veins; venation palmate, primary veins ca. 8, midrib indistinct, palmate veins branching dichotomously toward leaf margin, tertiary veins percurrent or reticulate. Inflorescences axillary, dichasial cymes arising directly from rhizome, branched 3–4 times; peduncle crimson, ca. 14 cm long, sparsely pilose; bracts usually persistent, pale yellow to pinkish, orbicular to widely ovate, apex obtuse to acute, first pair ca. 0.6 cm across, glabrous, margin denticulate with rows of gland-tipped teeth or glandular hairs, bracts of upper inflorescence similar but smaller. Staminate flower: pedicel 1–1.5 cm long, sparsely pilose or glandular hairy, tepals 4, outer 2 very widely ovate to orbicular, 0.9–1.2 cm long, 0.8–1.1 cm wide, white to pinkish, abaxially sparsely pilose and glandular hairy, inner 2 obovate to oblanceolate, white to pinkish, 0.8–1 cm long, 0.2 –0.35 cm wide; androecium zygomorphic, 0.3–0.5 cm across; stamens golden yellow, 23–38; filaments fused at base; anthers obovate, ca. 1 mm long, apex truncate or retuse, equal or shorter than filaments. Pistillate flower: pedicel ca. 1 cm long, sparsely pilose or glandular hairy, tepals 3, outer 2 suborbicular or broadly ovate, white to pinkish, abaxially sparsely pilose and glandular hairy, 0.8–1.2 cm long, 0.7–1.2 cm wide, inner 1 obovate to oblanceolate, white, ca. 0.8 cm long, 0.3 cm wide; ovary trigonous-ellipsoid, ca. 0.5 cm long, 0.4 cm thick (wings excluded), pale yellow, pinkish, pilose and glandular hairy; 3-winged, wings unequal, pilose and glandular hairy, pinkish, lateral wings narrower, narrowly crescent-shaped, 0.15–0.3 cm wide, abaxial wing crescent-shaped, 0.3–0.4 cm wide, margin slightly erose, hairy; locule 1, placentation parietal; placentae 3, each 2-branched (based on field observation of the cross-section of an ovary in a young flower); styles 3, golden yellow, ca. 0.25 cm long, fused at base into a short column; stigma spirally twisted. Capsule not seen.

Distribution and ecology:–– Endemic to central Guangxi ( Figure 3 View FIGURE 3 ). Growing on semi-shaded boulders on concaved, moist mossy limestone, elevation ca. 350 m. Very rare; currently known only from one locality with less than ten individuals.

Etymology: –– The specific epithet refers to the suborbicular peltate leaves.

Notes:–– Begonia ufoides somewhat resembles B. umbraculifolia Y. Wan & B.N. Chang (1987: 322) , another peltate species in southwestern Guangxi, differing in the rhizome internodes to 0.5 (vs. 4−6) cm long, petiole 7−11 (vs. 10−40) cm long; leaves coriacellate to coriaceous (vs. chartaceous), upper surface flat (vs. bullate between veins) with a rounded (vs. acute to shortly acuminate) apex; pedicel of pistillate flower ca. 1 (2.7–4) cm long. Begonia ufoides also resembles B. phuthoensis H.Q. Nguyen (2004: 105) in having peltate leaves with spiderweb-like lateral veins. However, Begonia ufoides markedly differs in the much shorter petiole (7−11 cm vs. 25−30 cm long), smaller leaves (4.5−9 × 4–8.8 cm vs. 9−18 × 7–12 cm), relatively flat upper surface (vs. bullate between veins), rounded apex (vs. shortly acuminate), peduncle longer than petiole (vs. shorter) and pilose (vs. glabrous). A comparison of salient features of the three species is presented in Table 1 View TABLE 1 .