Viola tenuissima Chang

Herbs perennial, small, 5-7 cm tall. Rhizome short, densely covered with few scales. Stems greenish when dry, filiform, slender, glabrous. Basal leaf usually 1, long petiolate; stipules narrowly ovate, 2-2.5 mm, margin subentire or sometimes remotely and inconspicuously serrate; cauline leaf petiole linear, long, to 5 cm, slender; cauline leaf blade abaxially glaucous, adaxially green, cordate, 1-1.5 × 1-1.5 cm, both surfaces sparsely white puberulous or subglabrous, base deeply cordate, lateral auricular lobes rounded and often overlapping, margin remotely and large serrate, apex shortly or inconspicuously acuminate. Flowers solitary in upper leaf axils, yellow; pedicels filiform, 2-3.5 cm, slender, 2-bracteolate above middle; bracteoles linear, small. Sepals very narrow, linear, ca. 5 × 0.6-1 mm, basal auricles very short, glabrous, margin narrowly membranous, apex truncate. Upper petals oblong, ca. 1 × 0.3 cm, lateral ones not barbate, slightly longer than upper ones, anterior one narrowly obovate, ca. 1 cm × 4-7 mm, base purple striate; spur 3-5 mm, 1-1.5 mm in diam., apex small and obtuse. Ovary glabrous, red punctate; styles 2-2.5 mm, base geniculate, apex 2-lobed, lobes obtuse. Capsule subglobose, ca. 4 mm in diam., red punctate. Fl. Jun-Jul, fr. Aug-Sep.

N Guizhou, W Sichuan.

● Mountain forests, rock crevices in shaded and moist places; 2300-3300 m.