If your garden is anything like mine at this time of year, it is peppered with these beautiful little treasures: common violets (Viola sororia). These blue, purple, and sometimes almost white, small flowers return yearly to brighten my flower beds, lawn, and even the crack in my concrete stairs. Still, I have never once intentionally planted one! My curiosity was piqued as I sat on my front porch looking at this bounty that I did nothing to deserve.
The ability to appear and spread in my garden without my intervention intrigued me. I discovered that the Viola family has somewhat of a superpower where reproduction is concerned. They can reproduce sexually, asexually, and also clonally. Early in the spring, insect pollinators include several native bees, butterflies, and wasps, with butterflies being the primary pollinators. Evidence indicates that some viola flowers transform over the season to accommodate this variety of pollinators. Once fertilized sexually, the developed seeds are flung up to several feet when the seed pods dry out and split open. But there’s more! Each tiny seed has a fleshy, oil-rich appendage called an elaiosome. This elaiosome attracts ants who transport the seeds to their nests to feed the fatty treat to their larvae, and the intact discarded seeds germinate. Explosive seed distribution plus ant transportation ensures this wide seed dispersal in my garden. For more information, see An Ecology of Spring Wildflowers.
But Viola has a plan B! If insect pollinators are limited when the weather is too cold or too wet, secondary self-fertilization occurs in small budlike, petal-lacking flowers located at ground level. Although these seeds do not include extraneous genetic material, they are fertile and ensure the violet’s survival in less-than-perfect conditions. Their final superpower is the ability to spread vegetatively by producing stolons. In this way, they end up creeping across my garden and creating many new clonal plants. All in all, this bounty of violets is a blessing to one very lazy gardener and the wildlife that enjoys it.
Violas are an important early nectar and pollen source for native bees and other pollinators. They are also the host plant of many fritillary butterflies (fourteen species of greater fritillaries and sixteen lesser).
Chasmogamy – sexual reproduction
Cleistogamy – asexual reproduction
Myrmecochory – ant seed dispersal
- Carol Gracie, Spring Wildflowers of the North East, New Jersey: (Princeton University Press, 2012)