- Pest Type: Weed
- Crops Affected: Wheat, Cotton, Potatoes, Soybeans, Corn
- Scientific Name: Euphorbia maculata
- Pest Order: Euphorbiaceae
Spotted spurge is a prostrate to ascending, branching, mat-forming summer annual, generally about 40 cm in diameter. Stems and foliage exude a milky sap when injured.
Reproduction is by seed. Seeds germinate from early June to late summer. Spotted spurge does not root at the stem nodes. Seed production can begin when the emerging plants are only a couple of weeks old.
Hypocotyls are short, pink, and smooth. Cotyledons are oval, green on the upper surface, maroon on the under surface, and have short purple petioles.
Young leaves are opposite, hairy, green, often with a maroon blotch on the upper surface. The lower surface is maroon with a powdery coating. Leaf bases are unequal, and the petioles are reddish. Stems are pinkish and densely hairy.
Stems and leaves are similar to those of the immature plant. Leaves are opposite, oblong, or somewhat egg-shaped or linear (5-15 mm long and less than half as wide; widest below the middle), on short petioles subtended by lanceloate stipules. Leaf margins may be toothed toward the apex.
Flowers are present from July to September in the axils of the upper leaves. Flowers appear to be single but are composed of several male and one female flower aggregated into a small cluster and surrounded by a cup-like structure. The fruit is a 3-lobed, 3 seeded capsule, 1.5 mm long, with stiff hairs on the surface. Seeds (1 per cell) are about 1 mm long, 4-angled, oblong or egg-shaped, grayish brown to reddish brown, with transverse ridges. Seeds become sticky when wet.
Stems persist for only a short time after frost.
Spotted spurge is a common summer weed of landscapes, turfgrass, and nursery crops. It is also found in cultivated fields, gardens, and waste areas. It survives on dry or sandy, low-nutrient soil and on compacted or disturbed sites and thrives in container-grown nursery crops.
This weed is found throughout the eastern and midwestern United States, and on the Pacific Coast. Spotted spurge is also common in Mexico and Central America.
Prostrate spurge is very similar to spotted spurge but has pale green leaves and often roots at the lower stem nodes. Nodding spurge is somewhat similar, but the stems are ascending or almost erect.