Beware of the Common Blue Violet, an attractive innocuous-looking pass-along plant! Viola sororia (synonym V. papilionacea), a charming eastern North American native plant, is often part of plant sales or gifts from other gardeners. It can, however, develop into an invasive and persistent weed in Roanoke Valley lawns and gardens.
How does one simple plant become a garden monster?
- Seed development and dispersal are responsible for its extensive spread
- Extensive fibrous roots on older plants make removal by hand weeding challenging and exacting.
Other native blue violets such as Viola cucullata (synonym V. oblique), the Marsh Blue Violet or Hooded Blue Violet share similar characteristics.
Common Blue Violets as well as most true native violets produce two kinds of flowers:
- Infertile colorful and showy flowers bloom from spring–to–early summer. They are composed of five green sepals, five petals and some stamens (male reproductive parts). The petals consist of a flat spurred lower petal (a landing spot for hoodwinked insects), two side petals or wings (bearded in V. sororia), and two upper petals.
These showy flowers attach to the plant crown the plant’s shortened, almost nonexistent stem – on long smooth petioles. They are the same height as the leaves or rise slightly above them. Flowers display a variety of colors from deep to light blue to white with varying amounts of blue stripes. They have no scent.
- Fertile (both male and female reproductive parts present) summer flowers with undeveloped or no petals form and often persist at the plant’s base. They never open and self–pollinate within closed colorless sepals. These hidden or cleistogamous (closed and united) flowers produce thousands of seeds and may shoot them up to nine feet.
The development of substantial numbers of cleistogamous flowers throughout the summer and into the autumn, plus the phenomenal seed quantities produced lead to the potential germination of thousands of plants. Many new plants appear almost as if by magic in lawns and great distances away from initial plantings because of the violet’s forceful long–range seed dispersal.
Leaves of the Common Blue Violet are heart-shaped, slightly lobed with blunt teeth and pigmented a deep–green color. They attach to the plant crown, as do the flowers, with long smooth petioles. Foliage and plants are frost hardy and remain evergreen, but may die when covered with snow and ice. Plants do not form runners but ultimately form a dense, fibrous root system. Neighboring plant roots may tangle making eradication tough and difficult.
Botanical Names for Common Blue Violet
Viola sororia, the Common Blue Violet, is one species in the complicated genus Viola. Some taxonomic authorities (plant–naming experts) set the species number at 125, others as high as 400.
Try looking up this plant name on the Internet or in a garden book. V. sororia has many synonyms – alternative scientific names used for a single plant – as well as vernacular or common names. There may be as many as six synonyms to distinguish this plant in any dozen randomly selected web sites or plant books. Sometimes, the spellings may even be different.
This naming uncertainty often results in confusion for professional horticulturalists along with gardeners and landscape professionals. Here are some of the more scientific synonyms for V. soria:
- Viola floridana,
- Viola latiuscula,
- Viola palmata var. sororia,
- Viola (papillionacea) papilionacea,
- Viola (papillionacea) papilionacea varpriceana, and
- Viola priceana.
Contemporary and recently revised plant books may contain up–to–date information. However, it pays to be conscientious and not let ones–self become confused. The Common Blue Violet, V. sororia, was until recently identified as V. papilionacea. Some writers spelled it as V. papillionacea. A form with white blue–streaked flowers merited the scientific designationV.papillionacea var priceana or V.papillionacea forma priceana , the common name Confederate Violet.
The Common Blue Violet is also the state flower of Wisconsin, Illinois, Rhode Island, and New Jersey Names sometimes include:
- Sister Violet,
- Common Meadow Violet,
- Purple Violet,
- Woolly Blue Violet,
- Hooded Violet,
- Wood Violet, and the form
- Confederate Violet.