Euphorbia peplus

Also know as petty spurge. Is often classified as an annual weed however the toxic sap content of this plant is a powerful medicine. It is a natural remedy for skin cancers like actinic keratosis, Please make sure that you use this under the supervision of a qualified herbal practitioner. 

Prefers a well drained but moist soil. Plant in full sun or partial shade. Height 50cm. Will self seed so remove flowers before they go to seed.