This herbaceous annual plant is on the decline in lowland areas of Scotland. It prefers arable fields and disturbed ground and is most common now on the Western Isles machair, or low-lying fertile plain.
The greenish-yellow flowers are formed in a tiny and petal-less cluster enclosed in a greenish bract which has finely serrated lobes, usually two large with one small lobe. Below this the leaves fan out in a circular formation, and are oval in shape and also finely serrated at the outer edge.
The leaves and flowers branch out of the top of a single hairless stem, which splits into three or five stems half way up above a symmetrical whorled arrangement of three or five leaves. This configuration has given rise to the nickname ‘Umbrella Milkweed.’ It is also known as ‘Mad woman’s Milk,’ likely due to the toxic milky sap that is produced from the stem. This ‘milk’ was used as an old folk cure for warts, hence its third nickname ‘wart-spurge.’