Leonurus cardiaca seed

It grows to around 60 cm to 1 m in height, with roughly serrated and lobed leaves, with flowers forming from the leaf axils on the upper parts of the plant from June to August.Easy to distinguish from other similar plants as it has a square stem with opposing leaves.Flowers are small and pink to lilac in colour.Medicinally used as a heart tonic, a mild sedative,and also used to minimise pre-menstrual pain, and by midwives in years gone by, hence its common name of Motherwort