Invasive Species Sheet - Cypress Spurge

Invasive Species Identification Sheet

Cypress Spurge (Euphorbia cyparissias L.)

- herbaceous perennial; invades roadsides, pastures
- has many stems connected underground (colonial)
- leaves blue-green; exude milky sap when injured
- leaves very narrow, mostly alternate (or in a spiral)
- flowers in umbels with usually 10 or more main branches

The flowering part of the plant begins with upright, branching stems leaving the top of the leafy mainstalk. The stems may fork. At the forking point are eye-catching, petal-like, yellowish green bracts. Some are heart-shaped. In Cypress Spurge, bracts often are purplish or reddish with age. Above the first set of bracts, more stems each lead to a smaller pair of bracts. Above these petal-like bracts are groups of petal-less flowers. A single female flower sticks out of each group (more obvious as the tiny, fruit capsule develops). The entire group of flowers comes out of a cup-shaped structure (a cyanthium) which is present in all Spurges (genus Euphorbia). The tiny fruit capsule is 3-parted and is green in contrast to the yellowish or reddish bracts.

In New England, the species most likely to be confused with Cypress Spurge is another non-native called Leafy Spurge (Euphorbia esula L.), which is a noxious rangeland weed in the western USA . The most easily recognized difference is in the leaves. Cypress Spurge leaves are strap-shaped, generally less than 1/8" wide and no more than 1 1/4" long. Leafy Spurge leaves are always wider than 1/8" and can be up to 1/4" (or even 3/10") wide with a length of 1"-2" (or even more than 3"). Cypress Spurge leaves are densely packed on the stem, especially on infertile sites. Typical stem height is 6"-18" tall depending on soil type and rainfall.

In New England, Cypress Spurge (and the less common Leafy Spurge) may threaten grassland habitat restoration.