Description from Flora of China
Viola uniflora Linnaeus var. orientalis Maximowicz, Enum. Pl. Mongolia, 81. 1889; V. conferta (W. Becker) Nakai; V. orientalis var. conferta W. Becker; V. xanthopetala Nakai.
Herbs perennial. Rhizome usually erect, sometimes obliquely ascending, 1-3 cm, robust, ca. 5 mm in diam., densely noded; roots numerous, white to yellowish brown, to 10 cm, with numerous filiform rootlets in lower part. Stems erect, 6-10 cm tall, usually puberulous. Stipules small, adnate to petiole only at base, free part ovate, 1-2 mm, margin entire or remotely serrulate; basal leaf petiole 3-10 cm; blade ovate, broadly so, or elliptic, 2-4 × 1.5-3 cm, abaxially puberulous, adaxially subglabrous, base cordate, sometimes subtruncate, margin obtusely serrate, apex acute; cauline leaves 3(or 4), upper 2 very shortly petiolate or subsessile, subopposite, lower ones shortly petiolate, above middle of stem. Flowers yellow, ca. 2 mm in diam., usually 1-3 in cauline leaf axils; pedicels 1-3 cm, white puberulous, sometimes glabrous, 2-bracteolate at upper part; bracteoles usually opposite, sometimes alternate, ovate, small, 1-2 mm. Sepals lanceolate or oblong-lanceolate, 5-7 mm, apex acute, basal auricles suborbicular, short. Petals obovate, upper and lateral petals curved toward outside, upper ones dark purple striate, lateral ones inside conspicuously barbate, anterior one shorter, 1-1.5 cm (spur included); spur saccate, short, 1-2 mm; spur of anterior stamens ca. 0.5 mm wide. Ovary glabrous; styles slightly straight at base, gradually thickened upward; stigmas capitate, with several series of long beards on lateral sides. Capsule greenish, ellipsoid or oblong, 7-12 mm, often dark purple punctate. Seeds white to brownish, ovoid-globose, ca. 2 mm. Fl. Apr-May, fr. Jun-Jul. 2n = 12.
Sparse forests on mountains, forest margins, thickets, grasslands on mountain slopes; 100-1100 m. Heilongjiang, E Jilin, Liaoning, E Shandong [Japan, Korea, Russia].