Charlock, commonly known as Wild mustard, is a hardy annual herb, which grows in arable and disturbed ground throughout agricultural Scotland. It can also be found in wasteland, roadsides, rubbish sites and even popping up in garden lawns.
It has many branched stems which are covered in down-turned hairs, and has more of a loose cabbage-y look to the leaf arrangement.
Leaves are spear-shaped, wide, with assymetrical teeth and shallow, pointed lobes. They can sometimes appear purple as well as green. Leaf stalks are often reddish or purplish-green in colour. Upper leaves tend not to have any stalks. A few small stiff hairs grow along the stems, and the upper part of the stem is branched, hairy and sometimes purple.
The flowers grow in clusters on blunt racemes, forming a rounded end to the stems. Pale yellow cruciform petals like most brassicas, with four spade-like petals per flower, each flower about 25mm in diameter. The 4 sepals drop off easily when the flower opens.
The fruit is similar to that of rape, a long stiff siliqua with a seedless ‘beak’ at the end. Siliques are about 3-4cm long and finely veined. The seeds are round and black.
The name Sinapsis is from the Greek for mustard. Arvensis means ‘from the field’ in Latin. It has also been known as field mustard.
The leaves of the wild mustard are edible when young, but the seeds are slightly toxic.