Description
Creeping perennial growing to 6 in (15 cm). Has toothed oval leaves, and attractive, violet-blue or white flowers with a 5-petaled corolla.
Habitat & Cultivation
Native to much of Europe and Asia, sweet violet is a common wayside plant also found along roadsides and in woodlands. The flowers and leaves are collected in spring, the root in autumn.
Parts Used
Flowers, leaves, root.
Constituents
Sweet violet contains phenolic glycosides (including gaultherin), saponins (myrosin and violin), flavonoids, an alkaloid (odoratine), and mucilage.
History & Folklore
In classical myth, sweet violet was associated with death, but classical physicians also knew it as an effective emetic and cough remedy. The 17th-century herbalist Nicholas Culpeper stated that: “All the violets are cold and moist while they are fresh and green, and are used to cool any heat or distemperature of the body either inwardly or outwardly.”
Medicinal Actions & Uses
Sweet violet flowers and leaves have a gentle expectorant and demulcent action and they induce light sweating. They are often used as an infusion or syrup for treating coughs, chest colds and congestion. They are used in British herbalism to treat breast and stomach cancer. The root is a much stronger expectorant and, at higher doses, is emetic.
Research
Iranian researchers investigated the use of two drops of sweet violet essential oil applied to the nostrils as a remedy for insomnia. The study, which lasted a month, found positive improvements in sleep measurements in those using the oil. A 2015 study of children with asthma concluded that sweet violet syrup helped to reduce symptoms of dry irritable cough.
Related Species
The related dog violet (V. canina) has approximately the same uses as sweet violet. The Chinese V. yedoens is prescribed for hot swellings and tumors, mumps, and abscesses. See also heartsease (V. tricolor).