Viola sororia (Common Blue Violet)

USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner’s Sons, New York. Vol. 2: 549.

Where Commonly Found: Forests, forest edges, meadows, fields, woodlands, CT, MA, ME, NH, NY, RI, VT.
How to Identify:
(For unfamiliar words: Wikipedia Glossary of Botanical Terms).
Go Botany Key to Viola sororia.
Missouri Botanical Garden webpage for Viola sororia.
Flower Type:  Violet blue/white scentless flowers appear in April to July, long-flowering, 3/4″ across with 5 rounded petals, including 2 upper petals, 2 lateral petals with white hairs (or beards) near the throat, and 1 lower insect-landing-pad petal.  
Leaf Arrangement:  Rhizomatic colonies give rise to basal rosettes.
Leaf Type:  Oval-ovate to orbicular cordate shaped leaves, yellowish green, in sunny, dry locations, to dark green, in partly-shaded, moister conditions, up to 3″ long by 3″ across,  with crenate or serrate margins. Some colonies exhibit hairs on leaves, while others not.
Height:  6″-9″
Seed Collection:  Seeds are flung outward by mechanical ejection from the 3-parted seed capsules/pods. .

Attracts:  Birds
Use:  Excellent Ground Cover for Pollinator Garden
Light:  Full Sun to Part Sun
Hardiness Zone:  3 to 7   USDA Zone Map
Soils:  Moist
Notes:  Common Blue Violet is a very nice low-growing, rhizomatic and re-seeding, annual ground cover that will form a dense, long flowering ground cover.
Native to Eastern, Southern and Midwestern US:  Biota of North America Program (BONAP) – North America Plant Atlas (NAPA).