Viola adunca
Viola adunca is a species of violet known by the common names hookedspur violet, early blue violet, sand violet, and western dog violet. It is native to meadows and forests of western North America, Canada, and the northern contiguous United States.
Description
This is a compact plant growing from a small rhizome system. The leaves are spade- or heart-shaped, sometimes with broadly wavy margins. They are generally 0.5 to 4 centimeters long. The single-flowered inflorescence grows at the end of a very thin peduncle reaching about high. The nodding flower is a violet about long, with five purple petals. The lower three petals have white bases and purple veining. The two side petals are white-bearded near the throat. The lower petal is spurred, often with a slight hook at the tip. It is a perennial blooming in late spring.There are several varieties of V. adunca; a white-petaled form has been noted in Yosemite National Park.
It has also been observed in Southern Ontario in tall grass prairies on the sand plain and in black oak savannas.