Euphorbia esula L.

Family: Euphorbiaceae

NOTE: This species is actionable only when found in field or vegetable seed for planting; tolerance applies.

Common names:  leafy spurge

Disseminule:  Seed

Description

Fruit a capsule, 3-chambered, 1 seed per chamber. Seeds broadly ovate to broadly oblong, subterete, 2.0–3.0 mm long, (1.1)1.2–1.6(1.8)mm in diameter; base of seed flat, oblique, with hilum usually obscured by persistent cartilaginous caruncle. Caruncle wrinkled, glossy to dull and crusty, orangeish to cream-colored, sessile, appressed obliquely to testa or extending out +/- horizontally. Raphe a prominent dark, thin, single or double line, extending longitudinally from the hilum to the chalazal area at apex. Chalaza prominent, round, slightly depressed. Testa lustrous, minutely reticulate and appearing smooth, greyish-white to greyish-brown and usually mottled or flecked with brown. Hilum darker than testa, narrowly wedge-shaped, grading into raphe. Embryo spatulate; endosperm readily visible.

Identification remarks

Comparison species

Euphorbia lucida Waldst. & Kit.

Euphorbia terracina L.

Distribution

Widespread in Europe; also found in China, Iran, Argentina, Canada and the United States.

Native to most of mainland Europe excluding the Scandinavian countries.

Habitat

Sub-tropic to sub-arctic climates, tolerating very dry as well as flooded conditions. Grows best in coarse-textured soils. Found in rangeland, riparian areas, waste areas, disturbed sites, roadsides, fields and pastures.

General information

Euphorbia esula is a deep-rooted perennial herb, up to 1 m tall. It is a very aggressive and difficult to control plant; roots or root fragments as deep as 2.8 m can produce shoots for many years under adverse conditions. Its seed is dispersed by explosively bursting fruit. The plant’s latex is toxic to cattle and horses (but not to sheep and goats). Infestations may result in severe reduction of available grazing land and major losses in livestock production. Euphorbia esula is one of ten species covered under the Federal Seed Act for which tolerance is applicable to its introduction (7 CFR 361.6(a)(2)).

Seeds

Seeds

Hilum (left) and caruncle (right) of seed

Chalaza of seed

Capsule

Seeds

Seeds

Chalaza of seed

Capsule