Fool's parsley
Aethusa cynapium
Importance
Common and widely distributed except in the north of England and Scotland, where it is local.
1. Annual to biennial with an unpleasant smell, this plant is poisonous and erect. Its stem is hollow and branched. Leaves are two to three fingered. Flowers July - August. © Alamy Ltd.
2. Cotyledons gradually narrow into a longer stalk.
3. First leaves are deeply divided into three lobes, each with two to three deep indentations.