Legal Classification in WI: Restricted.
Leaves: Leaves are linear, alternate, and have slightly wavy, smooth margins with a bluish green color. Leaves are 0.25-0.5″ wide and 1-4″ long.
Flowers: Late spring to summer. The flowers are small, green and are borne in clustered yellow-green bracts. These bracts develop in late spring and the flowers develop within the bracts by early summer.
Fruits & seeds: Seeds are 0.08″ long, oblong, gray to purple, and are borne in pods which contain three seeds. When mature, seed capsules shatter, scattering seeds.
Roots: Brown, woody roots with pinkish buds. Plants have both a taproot, which may extend to the water table and lateral roots that extend to 15′ beyond the main taproot.
Similar species: A number of native species also have white, milky sap (e.g. milkweed species and flowering spurge), but milkweed species have a distinct long seedpod and flowering spurge is easily distinguished by white flowers. Cypress spurge (Euphorbia cyparissias) is another non-native species that is often confused with leafy spurge. Cypress spurge has a similar flower, but is a shorter plant (6-15″ tall) with needle-like leaves.
• Invades grasslands, pastures, prairies, and old fields.
• Can drastically reduce (50-75%) productivity of rangelands.
For more information visit: http://dnr.wi.gov/topic/Invasives/fact/LeafySpurge.html
Photo released under creative commons license.