Besides being my original gateway to natural areas stewardship and rare plant illustration, I’ve learned that plants in the family Violaceae are amazing all on their own.
Usually equally disregarded by gardeners and stewards, they have a lot to teach us about survival. First of all, they produce two different kinds of flowers: the showy, often purple, chasmogamous flowers we are used to seeing in our lawns and parkways, and, in contrast, the almost minuscule cleistogamous flowers that hide well beneath the leaves and never really open, and are self-pollinated. Cleistogamous flowers are the image of plant reproductive laziness (or creativity or even desperation?): All the reproductive parts are snugly encased, with the pollen never leaving the flower – they germinate right inside the anthers so that the pollen tubes that grow from the pollen grains grow right through the anther into the stigma, bypassing the need for an insect vector. (But the downside of too much self-pollination effort can be losses of genetic diversity and population vigor, so there’s a cost to this strategy, too.) As herbaceous perennials, violets grow anew every year from their thickened above-ground stems, with new plants emerging from dormant buds at the base of the rosettes, with some species even sending out stolons or runners that periodically root and send up new sets of leaves and flowers.
Violets, therefore, have a three-pronged route to reproduction and survival: cross pollination by insects, self pollination, and clonal recruitment via runners. But wait – there’s more!!
Violets have these curious three-seamed seedpods that start out curled shyly downwards. When fully ripe, they stand up proudly and explode open, extending their reproductive range even further. But wait – there’s even more!
Like other native plants such as trilliums, they have little fatty packets attached to the seeds called elaiosomes (which seem to be the equivalent of Dove Bars for ants). The ants gather the seeds and bring them back to their nests, where the elaiosomes are enjoyed over the cold months. The rest of the seed is discarded and waits, enjoying optimal conditions of dark, cool and moist stratification before venturing roots down and leaves aboveground, usually much further from the parent plant than the projectile method might otherwise afford.
Violets are one of the perfect introductions to taxonomy –they’re SO ubiquitous – I mean, most urban and suburban blocks have at least one or two specimens, right? – but are also frustrating, because there are over two dozen different violets in Illinois, some of them requiring a good dichotomous key, a hand lens and persistence to sort out. So deceptively simple at first glance, they draw you in with a bit of a challenge.
Another consideration about violets – because the main vegetative and reproductive part of the plant is above ground, they are especially sensitive to fire. Research done on populations of Viola conspersa (now considered to be Viola labradorica) suggested that woodland burns could result in 90% or more population mortality of existing individuals. Perhaps this three-pronged reproductive approach is a response to occasional but persistent fire patterns in their habitats? (Just a question!)
Some characteristics to look for when taking a new look at this interesting family: leafy stem – or simple rosette? What color are the flowers? Feathery, plain or nearly absent stipule (a leaf-like part of the leaf base that is usually attached to the petiole (the elongated bit that connects the leaf blade to the stem)? Do the flower petals have beards? What about the leaves? Are they smooth or hairy? The full-grown leaves can be triangular, sword-shaped, round, heart-shaped, kidney shaped, large, or small as a quarter. Their margins can be serrated, incised, lobed, deeply lobed or almost smooth. And some prairie violets have leaves that are so deeply and finely lobed they blend right into the short grasses and sedges nearby!
What about habitat? Some are very specific to woodlands, prairies, fens, marshes, or sandy swales. How many different violets do you think you can find in a year’s worth of exploring?
And once you’re finally confident about your violets, just to make matters even more confusing, there is a tall upright violet that looks nothing like your lawn’s weedy compadre, the tall Hybanthus concolor, or Green Violet. Very rare around here, and monitored by Plants of Concern when it is found in Cook and Will County, it’s a bit more frequent downstate. But you’d never know it’s a violet! About two feet tall, with ovate/lanceolate leaves and inconspicuous, drooping flowers, most people would walk right by it.
And if you want to venture outside of Illinois to explore more in the family (of which there are 16 genera), check out the endemic Hawaiian violets that are woody shrubs!
From the Author:
Although everyone seems to consider me ‘the orchid lady’, finding something cool (one of our Plants of Concern species) in a neighbor’s yard piqued my interest in violets. It was right after my first assignment with POC, monitoring the threatened Dog Violet (Viola conspersa/labradorica). Turns out it was Viola striata, the cream violet. : ) It’s native here but I’m not sure if the population is from our region; we’d have to do DNA testing, I suppose, to be certain. I did a legal rescue of some of the plants when my neighbor’s house was sold after she passed away. (The new owner was more a fan of the Chemlawn look.)
For Further Reading:
For a basic key to our local violets, check out the Field Museum’s online key, developed by Bil Alverson and Jennie Kluse, based on the expert work of Dr. Harvey Ballard of Ohio University: http://fm1.fieldmuseum.org/keystonature/violets/