Plant of the week: Violet woodsorrel (Oxalis violacea)

Violet woodsorrel is the only native woodsorrel in Kentucky with lavendar to purple flowers.  All the remaining species have yellow flowers.  The use of this in the woodland garden is as a filler plant, filling in and under some of the earlier blooming species and I love this plant for the usual red blotching in the trifoliate (clover like) leaves (hence the name trinity grass) and for the fact that deer do not typically eat this species (because of the oxalic acid). Because it is sour tasting, many herbivores do not eat this plant and historically after sheep would overgraze pastures, this species would invade and thrive because the sheep would not graze it (hence the name sheep sorrel).  The oxalic acid gives rise to the genus name of Oxalis and of course violacea refers to the lavendar flowers.  It has also been called Indian lemonade as the Native Americans brewed a sour tasting beverage that was used to treat mouth ulcres, stomach distress, and urinary tract problems.  It has also been used to treat scurvy, as a fever reducer, diuretic, and appetite suppresant.  This is a diminuitive plant that only reaches 6" tall when flowering but it is very easy to grow in the woodland garden, in a rock garden, or any place with good well drained average soil.  It is quite drought tolerant and the sour tasting leaves add an interesting tart flavor to salads.  It has few natural pests and will spread to form a nice colony if it is planted in favorable growing conditions of part shade, well-drained slightly acidic soils.  The leaves and flowers typically "open" or unfold on sunny days and stay tightly bundled on cloudy and rainy days.  It is pollinated by primarily carpenter, cuckoo, mason, andrendid, and halictid bees.