Euphorbia oblongata is a hairy, rhizomatous herb growing to a maximum height of just over half a metre. It has oval shaped or narrow leaves with finely toothed edges which are 4 to 6 centimetres long. The foliage is green to yellow-green. The inflorescences hold tiny glandular flowers. The fruit is a spherical capsule about half a centimetre long which contains smooth brown seeds.

Several other tall non-native spurges may be found as garden escapes or casual introductions

The glands on the cyathium (the cup shaped structure that bears the male and female flowers) are rounded on the outer edge; the ovary and capsule are papillose (with small pimples or warts)

Photo of the plant in its habitat, with details of flowers and capsule

Various habitats including waste and disturbed ground, fields and verges.

Flowering from May onwards with fruit capsules from July.

Perennial.

This species is widespread and probably becoming more frequent in Britain

Rare in Leicestershire and Rutland. It was not recorded in the 1979 Flora survey of Leicestershire.

It is not listed in the current checklist (Jeeves, 2011)