Crooked Run Valley
violet woodsorrel (Oxalis violacea)
Ionoxalis violacea (L.) Small
Oxalis violacea L. var. trichophora Fassett
Sassia violacea (L.) Holub
CONFIRMATION STATUS: Pending confirmation.
TAXONOMY: The currently accepted scientific name for violet woodsorrel is Oxalis violacea L.
NATIVE STATUS: Native, United States.
GENERAL BOTANICAL DESCRIPTION:
Habit: A bulbous, stemless perennial typically growing 4-8" tall in which the long-stemmed leaves and longer, leafless flower stalks rise directly from the bulb.
Leaves: Violet woodsorrel consists of a small cluster of trifoliate basal leaves on long petioles that emerge directly from the ground. The petioles of the basal leaves are up to 4" long; they are whitish green to pale reddish green, terete, glabrous, and rather delicate in appearance. Individual trifoliate leaves are about 1" across and they open up during the day. Each leaf consists of three obcordate leaflets, inversely heart-shaped, often center-creased, with smooth margins. The leaves may turn purplish in response to cold weather or strong sunlight, otherwise, they tend to be greyish green. Both the upper and lower leaflet surfaces are hairless.
Flowers: Among these leaves, floppy umbels of flowers develop on peduncles up to 6" long. The peduncles are similar in appearance to the petioles. Each umbel has 2-5 flowers on slender pedicels up to 1" long; usually only 1-2 flowers per umbel are in bloom at the same time. The flowers are bell-shaped (campanulate) and about 1/3" (8 mm.) across. Each flower has 5 lavender or pale purple petals, 5 light green sepals, 5 inserted stamens with yellow anthers, and an ovary with an inserted style. Near the throat of the flower, the petals become greenish white with converging fine veins; they are oblanceolate in shape, often becoming slightly recurved toward their tips. The sepals are shorter than the petals; they are lanceolate in shape and hairless with purplish tips.
Fruit/Seeds: Slender pointed seed capsules develop that split into 5 sections, sometimes ejecting the light brown seeds several inches.
Roots: The root system consists of small bulblets with fibrous roots; these bulblets can multiply by forming clonal offsets.
REGENERATION PROCESS: Violet woodsorrel propagates itself by reseeding and clonal offsets from bulblets.
HABITAT TYPES: Habitats include mesic to dry black soil prairies, hill prairies, open upland forests, savannas, edges of wooded bluffs, limestone glades, and abandoned fields. It is usually found in higher quality natural areas where the original ground flora has been left intact.
SITE CHARACTERISTICS: Violet woodsorrel prefers full to partial sun and mesic to dry conditions. The soil can be rocky or loamy.
SEASONAL DEVELOPMENT: The blooming period occurs from mid-spring to early summer, lasting about 1-2 months.
GENERAL DISTRIBUTION: Violet woodsorrel is naturally found throughout most of the United States except the far western states (Oregon excepted) and northern New England (New Hampshire north). It is not reported as occurring in any Canadian province.
SKY MEADOWS DISTRIBUTION: To be determined.
IMPORTANCE AND USES: Primarily long-tongued and short-tongued bees visit the flowers for nectar or pollen. This includes little carpenter bees (Ceratina spp.), cuckoo bees (Nomada spp.), mason bees (Osmia spp., Hoplitis spp.), Andrenid bees, and Halictid bees (including green metallic bees). Less commonly, the flowers may be visited by small butterflies, skippers, and bee flies. Syrphid flies also visit the flowers, but they feed on the pollen and are non-pollinating. The oligophagous caterpillars of a brownish Noctuid moth, Galgula partita (the wedgling), feed on the leaflets of Oxalis spp. The seeds of Oxalis spp. are eaten to a limited extent by several upland gamebirds and songbirds, including the bobwhite, mourning dove, horned lark, field fparrow, grasshopper sparrow, Savannah sparrow, and slate-colored junco. The prairie deer mouse and white-footed mouse also eat the seeds of these plants. The cottontail rabbit browses on the foliage occasionally, even though it is mildly toxic because of the presence of oxalic acid.