Tuesday, October 20, 2015

Violet Surprise 2

Earlier in the season I found a violet with fringed leaves growing in an overgrown garden (the-biologist-is-in.blogspot.com/2015/05/violet-surprise.html). There are a few violet species which typically have similar fringed leaves (V. triloba, V. palmata, & V. pedata), but it is pretty clear that the plant I found doesn't represent any of these species. I identified the plant as being a novel mutant form of the Viola sororia (Common Blue Violet) that is growing all over the yard.

Earlier in the summer, we performed an accidental experiment involving lots of hosta plants. Most of them were green and a few were variegated. The deer immediately started eating the green hostas, with such vigor that they pulled some of the plants out of the ground. The variegated hostas remained untouched... for a while, at least. The result of this experiment is that the deer are hesitant to eat something that looks different from what they're used to.

I realized that violets are also considered delectable to deer when I planted some other violet plants into a garden bed and watched them repeatedly get nibbled to the ground. I find myself wondering if the survival of this fringed plant before I found it was due to its novel look. It could also be that the plant was just hiding better. Compared to the typical violet, the fringed leaves made this plant better camoflaged among the grasses and such which were growing around it.

Either way, I like the look of the plant and am hoping to propagate it further. V. sororia creeps along the ground, growing new branches while older sections of stem die with age. Over time a single plant will become many vegetative clones spread over a wider area. This is a slow method of propagating a violet, but fortunately the biology of violets provides a faster method.

Early in the growing season, a violet plant produces the stereotypical purple/violet flowers. In the heat of summer, flower production falls off. Once cooler weather arrives with fall, flowering starts up again. However, these flowers are different than the spring flowers. These flowers never open their petals and develop on very short stems, so remaining hidden at the base of the plant. Because they never reveal their reproductive parts, they're referred to as cleistogamous flowers. The flowers pollinate themselves and then develop more obvious seed pods. Once the seeds are mature, the seed pod rotates to point upwards and the seeds are forcefully ejected by the drying of the fruit sections.

A simple way to save the seeds is to wrap the pods in a simple loop of cellophane tape. The tape will remain attached to the pod as it ripens and rotates. When the fruit sections dry out, the seeds are forcefully ejected onto the sticky tape (as in the image at right) where they remain for collection.

If the parent plant is highly inbred, the seeds collected from a cleistogamous flower will represent near clones of the parent. Because of this feature, the seeds I'm collecting from the mutant V. sororia will likely grow to also have the interesting fringed leaves. (All Viola species share this pattern of flowering, including pansies.)