Euphorbia characias sub. wulfenii (Mediterranean spurge)
E. characias subsp. wulfenii is an upright, evergreen shrub with biennial shoots bearing linear to oblong, grey-green leaves and dense, spherical to cylindrical cymes of yellow-green flowers from early spring to early summer. All parts of the plant are highly toxic if ingested. The milky sap may cause irritation to skin and eyes.
Grow in well-drained soil in full sun. If necessary, add grit or sharp sand to the soil to improve drainage. Dislikes winter wet, so a gravel mulch will help avoid rotting. Will reach a height of 1.2m and a spread of 1.2m after 2-5 years.