- Family: Spurge Family – Euphorbiaceae
- Growing form: Perennial herb. With subterraneous runners.
- Height: 15–30 cm (8–16 in.). Stem branches flowerless. Containing latex.
- Flower: The small male and female ‘flowers’ lack a perianth and are borne in groups in the centre of a bowl-like involucre (formed by fused subtending bracts), the whole resembling a single greenish–lime green–almost white flower, which eventually often turns reddish. Nectariferous glands in cyathia sickle-shaped, with short points. Bracts ovate. Stamens numerous. Pistil of 3 fused carpels. Inflorescence a 9–18-branched compound umbel, branches unbranched or 2-branched.
- Leaves: Alternate, almost stalkless. Blade linear, narrow, round-tipped, with entire margins, bluish green–lime green. Branch leaves narrower than stem leaves, needle-like.
- Fruit: 3 mm (0.12 in.) long, 3-valved, grooved capsule with glands.
- Habitat: Graveyards, parks, yards, roadsides, waste ground.
- Flowering time: May–July.
With two thousand representatives, genus Euphorbia is a massive group amongst vascular plants. The group of species ranges from large spiny bushes to cactus-like succulents, and from large perennial herbs to quite small annuals, and many of these are popular potted house-plants like African milk tree, crown-of-thorns and poinsettia.
Cypress spurge is originally a perennial in Finland which has survived as a leftover from cultivation in e.g. abandoned dwelling places and sometimes spread close by into the wild. It spreads mainly through its surface runners and thrives in dry and poor land.
Cypress spurge looks like another related established alien leafy spurge (E. esula). The species differ from each other in size (leafy spurge is clearly shorter) and the form of the leaves: Cypress spurge’s leaf blade is linear, 1–3 mm (0.04–0.12 in.) broad and blunt-tipped while leafy spurge’s leaves are quite lanceolate, 3–8 mm (0.12–0.32 in.) broad, and the upper leaves on the flowering stem are usually sharp-pointed.