Despite the name, violets come in several colors including violet, white, and yellow. There are many different species, and the differences between those of the same color are often subtle. One thing the plants in eastern North America have in common is that they all bloom from April through May or June. Here I’ve identified a few that I often come across in southeast Michigan.
Marsh blue violets (Viola cucullata, Violaceae) can often be found in wet swamps, woodlands, and meadows. They can also be found growing in sufficiently moist lawns. There’s a low wet spot in my yard beneath a sugar maple where these plants flourish before they get mowed off with the grass. The gradual darkening of the petal color towards the center and the clubbed hairs between the petals are indicative of this species.
Pale violets (Viola striata, Violaceae) are just one of several white violet species. The purple stripes on the lower petal, absence of purple on the backs of the petals, and lack of any yellow set this species apart from other white violets. As with marsh blue violets, these plants prefer damp wooded areas.
Downy yellow violets (Viola pubescens, Violaceae) get their name from the fine hairs on the stems and backs of the leaves. They are identified by the laminar stipules, heart-shaped leaves, and presence of leaves and flowers on the same stems. Unlike many other violets, they seem to prefer somewhat drier soil. While I frequently find the marsh blue and pale violets in floodplains and near water, the downy yellows are often on higher ground.