Flower:

Flowers are small but distinct, mostly in clusters at the tips of branches, few in the lower leaf axils. A small cup, 1/8 inch across, holds the male and female flowers in the center. The rim of the cup has 4 white to pink, rounded petal-like appendages, each a thickened gland at the base that is green to red. The male flower anthers are yellow and nearly indistinct. The clump of styles of the single female flower in the center sit atop a round, 3-parted ovary on a short stalk that extends out from the flower center. Both the floral cup and the developing ovary are often blushed with red. The structure of this flower is called a “cyathium” and is common to all the Euphorbias.

Leaves and stems:

Leaves are opposite, oblong to oval oblong, 1/3 to 1 1/3 inch long and a third as wide, blunt or rounded at the tip, mostly stalkless or very short stalked, conspicuously asymmetrical sometimes with a shallow but distinct lobe on one side at the base. Leaf edges are variably toothed, mostly coarsely serrated all around the edge but sometimes only at the tip or on one side, or occasionally completely toothless. Surfaces on young leaves are covered with fine curled hairs, often in a single row, becoming hairless with age. The lower surface is typically light green and infrequently there is a splotch of red mid-leaf on the upper surface. Stems are often red colored, hairy on new growth, becoming smooth with age. The lower stem is erect though more spreading in the upper plant, and often drooping at the branch tips. Leaves and stems exude a milky sap when broken.

Fruit:

Fruit is a 3-sectioned capsule, strongly 3-sided, stalked, 1/10 inch wide, that develops rapidly from the center of the cyathium, the clump of styles persisting at the tip. The capsule initially hangs down, becoming erect at maturity, and is typically tinged red. Each section contains a single seed.

Seeds are oval-oblong, angular with rounded angles in cross-section, 1 to 1.6 mm long, slightly wavy on the surfaces, dark brown sometimes with a paler coating that may persist only along the angles.

Notes:

Nodding Spurge, formerly known as Chamaesyce nutans, is relatively common throughout SE Minnesota, though often overlooked. While it can become locally weedy in gardens and lawns in both dry and moist locations, historically it appears to have a strong affinity for sandy soils along lake shores and river banks. It is fairly easily distinguished from the other spurges by its open, upright to spreading branches with nodding tips. While in some areas of the country it can grow to heights of over 2 feet, it more commonly stays under a foot tall in Minnesota.