Pungent hairless plant reaching over one metre in height. Stems stout, becoming hollow when old. Upper branches usually opposite. Flowers yellowish in dense umbels without sepals.

Photograph of the plant in habitat

Hedge-banks, woodland margins and roadsides. Often seen near the sea.

April to June.

Biennial.

Fairly common near to the coast in England and Wales it is now spreading inland, probably aided by heavy salting of roads which seems to reproduce coastal conditions on the roadside verges.

Becoming more common in Leicestershire and Rutland especially near to well salted roads. In the 1979 Flora survey of Leicestershire it was found in only 4 of the 617 tetrads.

In the current Checklist (Jeeves, 2011) it is listed as Alien (archaeophyte); rare but locally frequent where it occurs