Begonia pedrabrancensis

Subshrub, erect, delicate, rupicolous, ca. 40 cm tall, glabrous to microscopic glandular trichomes. Cystoliths present, best seen in hyaline structures. Stems erect, internodes 1 – 1.6 cm long, vinaceous, with microscopic glandular to glabrescent. Stipules inconspicuous, persistent, ca. 5 × 0.5 – 1 mm, triangular, apex setiferous, margins entire, glabrous, subcarnose when fresh, scarious when dry. Leaves simple, petioles 0.5 – 1 cm long, vinaceous to pinkish, glabrous, leaf blades basifixed, (8.3 –) 9.9 – 13 × (1.6 –) 1.9 – 2.3 cm, entire, lanceolate, inconspicuously asymmetrical, carnosus, base obtuse, margins dentate, apex acuminate, adaxial surface glabrous, shiny green, abaxial surface glabrous, vinaceous to dark vinaceous on the veins, venation craspedodromous, 6 pairs of alternated secondary veins. Inflorescence in 4 - branched cymes, bearing up to 4 flowers because of temporal dioecy, 3 – 4 cm long (including the rachis), up to 4 cm long when fruiting, rachis (1.8 –) 2.4 – 2.8 cm long (up to same size when fruiting), glabrous, reddish on basal portions to pinkish distally. Bracts persistent, 1 – 2.5 × ca. 0.5 mm, triangular, apex setiferous, margins entire, glabrous. Staminate flower: pedicels ca. 10 mm long, white to pinkish, glabrous, tepals 4, external pair 6 – 7 × ca. 3 mm, ovate, apex acute, margins entire, white, membranaceous, with microscopic glandular trichome on dorsal surface, internal pair ca. 4 × 1.5 – 2 mm, elliptic, apex acute, margins entire, white, membranaceous, glabrous, stamens ca. 17, ca. 2.5 mm long, filaments ca. 0.5 mm long, free, connective projecting, obtuse to truncate, anthers ca. 2 mm long (including connective), oblong, extrorse, yellow. Pistillate flower: pedicels ca. 2 mm long, pinkish, glabrous, bracteoles 2, persistent, located alternately on the pedicel, triangular, 1.5 – 2 × ca. 0.3 mm, white-pinkish, tepals 5, white, unequal, 4 largest, 4 – 5 × 1 – 2 mm, 1 smallest, ca. 3 × 0.5 mm, lanceolate, apex acuminate, margins entire, membranaceous, with microscopic glandular trichomes on dorsal surface, ovary 3 - locular, ca. 5 × 3 mm, white, microscopic glandular trichomes, wings ca. 1.5 mm wide, equal, involute, pinkish, placentae entire, stigmas 3, ca. 2.5 mm long, bifurcate, branches spiraled, yellow. Capsule 11 – 14 × 8 – 9 mm (including wings), basally dehiscent, glabrous, light brown when mature, elliptic, peduncles 2 – 4 mm long, glabrous, brown, wings 3, equal, involute, rounded, 10 – 12 × ca. 3 mm, locular region ca. 12 × 3 mm, ovate, glabrous, seeds oblong.