Viola biflora L.

Viola species are annual or perennial or rarely undershrubs. Roots rhizomatous or not. Stem present or sometimes absent. Leaves simple, in rosette or not, basal, cordate to ovate-triangular, margin entire, serrate-dentate to pinnatisect, petiole slender to sometimes winged, stipules lanceolate-ovate, margin entire, persistent, free or adnate to the petiole. Flowers bisexual, zygomorphic, irregular 1-2 on long axillary pedicels, usually dimorphic (normal and cleistogamous flowers), white, voilet or purplish, bi-bracteolate, sepals 5, subequal, base usually auriculate, persistent, petals 5, subequal, erect or spreading, lateral ones largest, spurred basally. Stamens 5, hypogynous, filaments short, anthers 2 loculed, free or connivent around ovary, tipped with triangular nectariferous membranous appendages, extending into anterior spurs, within spur of corolla. Ovary superior, sessile, 3 carpellary, ovules many placentae parietal, style erect or slightly curved, stigma variable, triangular or lobed, obtuse or truncate, erect or beaked. Fruit capsule, tri-valved elastically, loculicidal, globose. Seeds many, ovoid-globose, surface smooth, shiny, embryo straight, cotyledons rather thick.

Viola species flowers are complete, bisexual, i.e., with functional male (androecium) and female (gynoecium), including stamens, carpels and ovary or rarely unisexual. Pollination is entomophilous i.e., by insects, or cleistogamy i.e., by self or allogamy i.e., by cross pollination. Flowering/Fruiting: April-August/July-October.

Seeds may be dispersed by autochory i.e., self dispersal, anemochory i.e., wind dispersal, zoochory i.e., dispersal by birds or animals, anthropochory i.e., dispersal by humans.

Annual or perennial herb, about 10-30 cm tall. Roots rhizomatous, slender, stout with many thick root hairs. Stems few to several, slender, erect or decumbent, 2-5 noded, glabrous or pubescent. Leaves simple, orbicular-suborbicular, broadly ovate to reniform, about 1-6 x 0.8-4.5 cm across, base cordate, margin entire to shallow crenate, apex deeply rounded or obtuse, subcoriaceous, glabrous to sparsely hirsute on the veins above and sparsely puberulous beneath, about 5-7 veined, stipules lanceolate-ovate, margin entire or sparsely denticulate, apex acuminate, persistent, about 6-8 mm long, petiole slender, up to 10 cm long. Flowers bisexual, zygomorphic, bright yellow with purplish brown veins, about 0.5-1.5 cm across, irregular 1-2 on long axillary pedicels, about 1-8 cm long, usually dimorphic (normal and cleistogamous flowers), bi-bracteolate above the middle, opposite or subopposite in the upper part, sepals 5, subequal, linear lanceolate to oblong, base usually auriculate, margins scarious or ciliate at the lower parts, persistent, up to 7 mm across, petals 5, subequal, oblong-obovate, erect or spreading, about 7-15 x 3-6 mm long, lateral ones largest, spurred basally, spur erect, slightly curved or cylindrical, about 1-2.5 mm long. Stamens 5, hypogynous, filaments short, anthers 2 loculed, tipped with triangular nectariferous membranous appendages. Ovary superior, ovoid-oblong, sessile, 3 carpellary, glabrous, about 2 mm long, ovules many placentae parietal, style geniculate at base, stigma variable, triangular or lobed, clavate, beaked. Fruit capsule, tri-valved elastically, loculicidal, ellipsoid-oblong, about 4-9 mm across. Seeds many, ovoid-globose, embryo straight, cotyledons rather thick.

Viola species are susceptible to various insect pests, powdery mildews, spot anthracnose, rusts and smuts, affecting leaves, stems and roots.

Alpine grasslands, damp forest margins and rocky places, altitude 2500-3500 m.

Not evaluated (IUCN).

Used in folk medicine. Plant decoction used for cough; leaves are laxative, flowers antiseptic and roots emetic.