|Synonyms   |
Viola sororia, known commonly as the common blue violet, is a short-stemmed herbaceous perennial plant that is native to eastern North America. It is known by a number of common names, including common meadow violet, purple violet, the lesbian flower,  woolly blue violet, hooded violet, and wood violet.
Hairless common blue violets with purple flowers and bearded spurred petals have been variously called Viola sororia, V. affinis, and V. pratincola.   In the Chicago region, this hairless form is most frequently found in weedy areas such as old fields and lawns.  Hairy purple violets with blue flowers have been called "true" Viola sororia and are rarely seen outside of remnant wooded areas. 
A form with white flowers that have a purple center has been called Viola sororia fo. priceana (Confederate violet).
Viola sororia has several named hybrids: 
- Viola × bernardii (Viola pedaifida var. pedatifida × sororia)
- Viola × bissellii (Viola cucullata × sororia)
- Viola × cordifolia (Viola hirsutula × sororia)
- Viola × conjugens (Viola sagittata var. sagittata × sororia)
- Viola × insolita (Viola pedatifida var. brittoniana × sororia)
Beyond its use as a common lawn and garden plant, Viola sororia has historically been used for food and for medicine. The flowers and leaves are edible, and some sources suggest the roots can also be eaten. The Cherokee used it to treat colds and headaches. Rafinesque, in his Medical Flora, a Manual of the Medical Botany of the United States of North America (1828 – 1830), wrote of Viola sororia being used by his American contemporaries for coughs, sore throats, and constipation.
The caterpillars of fritillary butterflies feed on these plants. The plants also serve as food for wild turkeys, rabbits, deer, livestock, the mourning dove, the bobwhite, and the white-footed mouse. 
The common blue violet is also called the "lesbian flower" because in the early 1900s, lesbian women would give violets to the women they were wooing. This symbolized their "Sapphic" desire, so called because Sappho, a Greek lyric poet, in one of her poems described herself and her lover as wearing garlands of violets. This practice became popular in the 1910 – 1930 time period.
- "Viola sororia Willd.". Tropicos. Missouri Botanical Gardens – via The Plant List.
- "Viola sororia var. missouriensis (Greene) L.E.McKinney". Tropicos. Missouri Botanical Gardens – via The Plant List.
- Little, R. John; McKinney, Landon E. (2015). "Viola sororia". In Flora of North America Editorial Committee. Flora of North America North of Mexico (FNA). 6. New York and Oxford – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
- Wilhelm, Gerould; Rericha, Laura (2017). Flora of the Chicago Region: A Floristic and Ecological Synthesis. Indiana Academy of Sciences.
- Reznicek, A. A.; Voss, E. G.; Walters, B. S., eds. (February 2011). "Viola". Michigan Flora Online. University of Michigan Herbarium.
- Hilty, John (2016). "Common Blue Violet (Viola sororia sororia)". Illinois Wildflowers.
- 2003-04 Wisconsin Statutes & Annotations: 1.10 State song, state ballad, state waltz, state dance, and state symbols.
- Connecticut Plants, Connecticut Botanical Society