Euphorbia family (Euphorbiaceae)
Description: This plant is a summer annual that becomes 3-18" tall; it is low and spreading, but not prostrate. The stems are pinkish red, round, and hairless, except for a few fine hairs on new growth. The opposite leaves are up to 2" long and ¾" across. They are oblong, with short petioles and margins that are smooth or irregularly serrate. The lower surface of each leaf is light green, while the upper surface may have a red blotch in the middle. A few fine hairs may occur near the base of each leaf. The inflorescence consists of a small cyathium on a straight pedicel. Usually, several cyathia develop near the ends of each major stem when a plant is mature. A cyathium is a small cup-like structure containing the pistillate flower and one or more staminate flowers, which have neither true petals nor sepals. It is initially green, but often turns red in bright sunlight. On this particular species, the cyathium has 4 tiny petal-like appendages that are bright white. Eventually, a round tripartite fruit develops from the cyathium on a short stalk; it often turns red in bright sunlight as well. This fruit is noticeably larger than the flowers. The blooming period is mid-summer to fall, lasting about 1-2 months. There is no noticeable floral scent. The root system consists of a slender central taproot.
Cultivation: The preference is full sunlight, dry conditions, and poor soil. The soil can contain significant amounts of gravel, sand, or clay. Foliar disease rarely bothers the leaves, and drought resistance is excellent. This plant can reseed itself readily in sunny open areas.
Range & Habitat: The native Nodding Spurge is a common plant that occurs in nearly every county of Illinois (see Distribution Map). Habitats include dry upland areas of prairies, clay prairies, gravel prairies, thickets, openings in upland woodlands, fields and pastures (whether abandoned or still in use), areas along roadsides and railroads, poorly maintained lawns and gardens, and miscellaneous waste areas. This plant prefers disturbed open areas and it is somewhat weedy. This plant seems to be more common in rural than urban areas, possibly because of its intolerance to herbicides and frequent mowing of lawns.
Faunal Associations: The tiny flowers occasionally attract small bees, Syrphid flies, and wasps. These insects seek nectar primarily. The seeds are consumed by the Mourning Dove and Greater Prairie Chicken, and to a lesser extent by the Bobwhite and Horned Lark. The Wild Turkey has been known to eat the foliage, developing buds, and fruits, apparently without ill effects. Mammalian herbivores rarely eat this plant because of the poisonous white latex in the stems and foliage.
Photographic Location: The photographs were taken at the Windsor Road Prairie in Champaign, Illinois. Some flowers are in bloom in one of the photographs as their stamens are clearly visible.
Comments: The Nodding Spurge can be readily distinguished from other Chamaesyce spp. by its more erect habit, larger leaves, and mostly hairless stems. Several scientific names have been applied to the Nodding Spurge in the past, including Chamaesyce maculata, Euphorbia maculata, and Euphorbia preslii. Sometimes the entire plant will turn reddish green in response to strong sunlight and dry conditions.