Description from Flora of China
Herbs annual or perennial, shrubs, or subshrubs, sometimes scandent, rarely small trees. Leaves simple, usually alternate, sometimes opposite, with small or leaflike stipules, petiolate, margin entire, serrate, or dissected. Flowers bisexual or unisexual, rarely polygamous, actinomorphic or zygomorphic, solitary or in axillary or terminal, spicate, paniculate, or racemose inflorescences, 2-bracteolate, sometimes cleistogamous. Sepals 5, equal or unequal, imbricate, persistent. Petals 5, imbricate or convolute, unequal, anterior one usually larger than others, saccate, gibbous or spurred at base. Stamens 5; anthers erect, free or connivent or connate, connectives often dilated into membranous appendages; filaments very short or absent, anterior 2 stamens with spurlike nectary at base. Ovary superior, 1-loculed, 3-5-carpelled, syncarpous, with 3-5 parietal placentae each with 1 to many anatropous ovules; style simple; stigmas variously shaped. Fruit a loculicidal capsule, usually with elastic and abaxially carinate valves, rarely baccate. Seeds often carunculate; testa hard, nitid, often with oily bodies, sometimes alate; endosperm copious, fleshy; embryo erect.
Wang Chingrui. 1991. Violaceae. Fl. Reipubl. Popularis Sin. 51: i-v, 1-148.
Twenty-two genera and 900-1000 species: worldwide, but particularly in tropical regions; three genera and 101 species (36 endemic, three introduced) in China.
(Authors: Chen Yousheng (陈又生), Yang Qiner (杨亲二); Hideaki Ohba, Vladimir V. Nikitin)