B. subcoriacea

Culture

Comments

Known only from one limestone hill in southwestern Guangxi

Known In Cultivation

No

Endangered Status

Very Rare

Original Botanical Description or Link to

Ching-I PENG, Shin-Ming KU, Yoshiko KONO, Kuo-Fang CHUNG, and Yan LIU - Botanical Studies 49:405-418. 2008: Two new species of Begonia (sect. Coelocentrum, Begoniaceae) from limestone areas in Guangxi, China: B. arachnoidea and B. subcoriacea: “Plant monoecious; epipetric; perennial; rhizomatous. Rhizome rather stout, 5-15 cm long, 0.6-1.2 cm thick, internodes 0.4-1.2 cm long, brown, villous when young, glabrate when old. Stipules eventually caducous, triangular-ovate or narrowly so, ca. 1-2 cm long, 0.8-1.4 cm wide, brownish, herbaceous, keeled or weakly so, abaxially hairy (sometimes only along midrib), margin usually ciliate or ciliolate, sometimes eciliate on upper margin, apex aristate, arista 3-4 mm long, somewhat hornlike. Leaves 2-6 or more, alternate, simple, asymmetric, unlobed, widely ovate or suborbicular, base strongly oblique cordate, margin inconspicuously irregularly repandly denticulate and ciliolate, apex shortly acuminate, (10-)12-20(-22) cm long (basal lobes included), (8-)10-14(-17) cm wide, adaxially green, with or without white maculation between major veins, abaxially pale green, yellowish green or reddish, sometimes reddish near the major veins, subcoriaceous, flat, adaxially glabrous (sparsely gibbous when young), obviously nitid, abaxially tomentose on major veins, sparsely pilose on tertiary venation; venation basally 6-7-palmate, midrib distinct, pinnate along midrib, with 1-3 major lateral veins on each side, other primary veins dichotomously branching or nearly so, tertiary veins reticulate or percurrent, divergence angle 60-85°, minor veins reticulate, major (1° & 2°) veins on abaxial surface prominently raised, minor veins not raised; petiole terete, 9-20 cm long, 3-7.5 mm thick, greenish or brownish, tomentose (trichomes withered and turning brown when old). Inflorescences axillary, 1-6, arising directly from rhizome, diffusely cymose, branched 3-7 times; staminate flowers 20-60, carpellate flowers 10-32; peduncle well developed, terete, erect or ascending, 16-35 cm long, 2-2.5 mm thick, red, covered with reddish glandulose-pilose trichomes (trichomes 1.5-2 mm long); pedicels red, glandulose-pilose with reddish trichomes, ascending to pendent in staminate flowers (0.8-4.3 cm long), horizontal to pendent in carpellate flowers (1-1.6 cm long). Bracts caducous, oblong, margin ciliate (lower bracts) or eciliate (upper bracts), apex acute or obtuse, 1-10 mm long, 0.5-5 mm wide, greenish or reddish. Staminate flowers: tepals 4, margin entire, outer two orbicular or widely depressed ovate, base rounded or slightly cordate, apex rounded or obtuse, 6-9 mm long, 7-10 mm wide, greenish-yellow, usually reddish toward the base, abaxially glabrous (rarely with few glandulosepilose trichomes); inner two tepals obovate, base cuneate, apex obtuse, 4-6 mm long, 3 mm wide, yellowish, glabrous; androecium actinomorphic, spherical, ca. 4 mm across; stamens ca. 40-75, shortly golf-club shaped; filaments fused into a column, subequal, ca. 1.5-2.5 mm long (free part ca. 0.5 mm, column 1.5-2 mm); anthers 2-locular, slightly compressed, obovoid, apex truncate or slightly emarginate, 0.7-0.9 mm long, 0.5 mm wide, yellow. Carpellate flowers: tepals 3, margin eciliate, persistent or eventually caducous, not thickened in fruit; outer two tepals widely depressed ovate, 6-8 mm long, 9-10 mm wide, greenish-yellow, usually reddish toward the base, abaxially glabrous (rarely with few glandulosepilose trichomes); inner tepal obovate, base cuneate, apex rounded, ca. 5-7 mm long, 3-4.5 mm wide, yellowish, glabrous; ovary trigonous-ellipsoid, 6-7 mm long, 4-4.5 mm across, red, glabrous (rarely with few glandulosepilose trichomes), 3-winged; wings unequal, greenish- yellow; lateral wings narrower, ca. 2 mm tall, glabrous; abaxial wing crescent shaped or triangular, ca. 3-5 mm tall, 6-7 mm wide; locule 1; placentation intruded parietal (nearly throughout); placentae 3, each 2-branched; styles 3, fused at base (sometimes with protrusions between style branches), yellow, ca. 3 mm long, apically split into C-form; stigmas in a spiraled band. Fruit a dehiscent capsule, nodding, red when fresh, 6.5-11 mm long, 5-6 mm wide (wings excluded), apex with persistent styles; lateral wings 2-3 mm wide; abaxial wing crescent-shaped or triangular, 2.5-5 mm high. Seeds many, brown, ellipsoid or ovoid-ellipsoid, ca. 0.4-0.5 mm long, 0.27-0.3 mm across, chalazal end rounded, micropylar end obtuse, outer periclinal walls of mature seeds concave; collar cells elongated, straight, nearly rectangular.”