Downy Yellow Violet
Viola pubescens. Some scientists believe that after green, closely related yellow was the first color developed by flowers as they evolved showiness. Bright colors help to attract insects for pollination. While it seems odd that a flower called “violet” should be “yellow,” all yellow violets have at least a tad of blue, purple, or brown, usually in the form of petal lines that are part of their insect guidance system. About a dozen yellow violet species occur in North America. Downy Yellow Violet (Viola pubescens) is found in rich, loamy soil throughout eastern and central states. Although it bears beautiful, showy blossoms, few people realize that this and other spring-blooming violets also produce viable flowers that never open. Called cleistogamous flowers, they appear lower on the plant, sometimes under the ground and often later in the season. While they may never open, they nonetheless contain all the necessary parts to produce seeds, though they are not as viable as cross-fertilized seeds. This system may have evolved because so many violets appear early in the season, when insect pollination is chancier than in the warmer, insect-rich months. Not all violets produce cleistogamous flowers. Some summer species, such as Johnny Jump Ups (Viola tricolor), bear very colorful blossoms, can easily attract insects, and do not appear to need backups. Cleistogamous, incidentally, means “closed marriage.” The showy flowers that lure insects are called chasmogamous, or “open marriage.”