Scientific name: Begonia locii C.-I Peng, C. W. Lin & H. Q. Nguyen
English name:
Vietnamese name: Thu hải đường lộc
Other name:

Herb, monoecious, rhizomatous. Rhizome stout, creeping, to 30 cm long, 0.8 − 1.6 (−2) cm thick, internodes 0.5–1.3 cm long, subglabrous. Stipules deciduous, reddish to olive with red veins, ovate-triangular, 0.6–1.4 cm long, 0.5–0.85 cm wide, strongly keeled, abaxially sparsely velutinous along midrib, margin entire or sparsely ciliate-dentate, apex aristate, arista ca. 0.25 cm long. Petioles pale brownish-green to rwddish, terete, (11−) 20–25 (−33) cm long, 0.3–0.6 cm thick, densely villous. Leaves alternate, blade asymmetric, obliquely ovate, (9−) 11–22 cm long, 6.5–12.5 cm wide, broad side 3.2–7.4 cm wide, basal lobes cordate, 3.3–6.6 cm long, chartaceous, apex acuminate, base strongly obliquely cordate, margin denticulate and densely puberulous with pale magenta hairs, adaxially deep olive-green to maroon with light green zones along primary and secondary veins, sometimes embellished with small bits of silvery white spots, midrib veins forming a wide silvery white zone; upper surface densely covered by small raised cones each topped by a magenta hair, giving a wrinkled texture; abaxially pale green, purplish red between primary and secondary veins, reddish-white tomentose on all veins; venation palmate with 7–8 primary veins, midrib distinct, with 3–5 secondary veins on each side, tertiary veins red, percurrent or reticulate. Inflorescences axillary, arising directly from rhizome, dichasial cymes branched 3–4 times; peduncle 13–35 cm long, tomentose or subglabrous; bracts and bracteoles caducous, pale yellow-green, ovate to elliptic, orbicular, bracts ca. 0.8 cm long, 0.5 cm wide, margin gland-tipped denticulate, bracteoles similar but smaller. Staminate flower: pedicel ca. 1 cm long, tepals 4, outer 2 broadly ovate to orbicular, 9–12 mm long, 8–11 mm wide, abaxially white to pinkish, adaxially whitish, glabrous, inner 2 elliptic, white, 7–11 mm long, 3–4.5 mm wide; androecium zygomorphic, subglobose, ca. 4 mm across; stamens 35–60; filaments fused at base; anthers yellow, slightly compressed, obovate, ca. 1 mm long, apex retuse, shorter than filaments. Pistillate flower: pedicel ca. 1 cm long, tepals 3, outer 2 pinkish to white, suborbicular or broadly ovate, 8–11 mm long, 8–12 mm wide, inner 1 white, oblanceolate to obovate, 6–10 mm long, 3–5 mm wide; ovary trigonous-ellipsoid, sometimes strongly keeled at middle, 7–12 mm long, 3–4.5 mm thick (wings excluded), whitish, sparsely hirsute and glandular, 3-winged, wings whitish green to pinkish, unequal, lateral wings narrower, narrowly crescent-shaped to trapezium, 2.5–6 mm wide, abaxial wing crescent-shaped, 4.5–7 mm wide, sometimes with 2 very reduced wings running parallel along the side of the ovary, sparsely hirsute to glabrous, margin entire to hirsute; styles 3, fused at base, yellow to greenish, 3–4.5 mm long, stigma spirally twisted. Capsule trigonous-ellipsoid, 10–15 mm long, 4–5 mm thick (wings excluded), greenish or reddish when fresh, glabrous to hirsute; wings unequal, lateral wings 4–6 mm wide, abaxial wing crescent-shaped, 6–7 mm wide. Somatic chromosome number, 2n = 30.

Additional specimens examined

Vietnam. Lang Son, Huu Lung District, Huu Lien Commune, Tam Lai Village, E106°22’53”, N21°39’60”, elevation ca. 185 m, Peng 21938 (HAST).

Distribution and ecology

Begonia locii is endemic to Huu Lung Protected Area, Huu Lien District, Lang Son Province, Vietnam (Figure 3), occurring on semi-shaded limestone rock face, elevation 125–165 m.

Etymology

Begonia locii is named in honor of Professor Phan Ke Loc for his contribution to Vietnamese botany.

Notes

Begonia locii resembles B. luochengensis S.M. Ku, C.-I Peng & Yan Liu from Guangxi, China in leaf shape and maculation pattern, but is clearly distinct from the latter in the percurrent and spiderweb-like leaf venation (vs. pinnate) near the attachment of the petioles; upper leaf surface densely covered with small raised cones (vs. nearly flat); and hirsute (vs. glabrous) ovaries. The new species is also similar to B. pengii S. M. Ku & Yan Liu in leaf maculation pattern, vestiture, and hirsute ovaries, differing by the leaf basifixed (vs. peltate); bract margin denticulate and glandular (vs. denticulate and ciliate).