Motherwort
Leonurus cardiaca
The name says who it is for. The second name says what it does to the heart.
Overview
Motherwort carries its identity in its names: leonurus, lion's tail, for the shape of its leaf; cardiaca, of the heart, for its primary action; and motherwort, for the tradition of its use in women's medicine for conditions from anxiety through difficult menstruation through the labour complications that this plant was apparently trusted to ease. It is an upright, slightly prickly herb of old gardens, roadsides, and waste ground near human habitation that has followed settlement from its native Asia into Europe and then the Americas, and wherever it arrived it was adopted for the same cluster of uses. It calms. It steadies an erratic heart. It relieves the tension that settles in the chest. And it should not, under any circumstances, be used during pregnancy, which is a significant caveat for a plant so thoroughly associated with women's medicine.
Botanical Notes
An upright, branching perennial reaching 60–120cm with deeply palmate leaves — upper leaves with fewer, narrower lobes — and whorls of small, two-lipped, pale pink to white flowers with a prickly calyx from June to September. The sharp calyx tips persist on the dead stems through winter. Found on disturbed, nitrogen-rich soil near old habitation, roadsides, and waste ground throughout Europe and North America. The aerial parts contain alkaloids (leonurine, stachydrine), iridoid glycosides, diterpene alkaloids, and flavonoids with documented cardiovascular, uterotonic, and anxiolytic activity.
Lore & History
In the sixteenth century, the English herbalist John Gerard wrote that motherwort was "good for the trembling and shaking of the heart" — a description that is both poetic and biochemically accurate for a plant that acts on cardiac muscle. In European folk tradition it was given to women after difficult births to steady the heart and ease the post-partum state; it was used in the preparation of women about to give birth, in the management of anxiety before labour, and in the treatment of "hysteria" — the broad, convenient Victorian category for conditions that disturbed respectable composure. In Chinese medicine it is yi mu cao, the benefit-mother herb, with documented uterotonic activity used to manage post-partum bleeding and irregular menstruation. The same plant, the same uses, on opposite sides of the world.
Warnings
Do not use during pregnancy — motherwort is a significant uterine stimulant and may induce premature labour or miscarriage. Avoid during heavy menstruation. Those on cardiac medications, particularly antiarrhythmics or anticoagulants, should consult a medical practitioner before use — leonurine and other alkaloids have genuine cardiac activity that may interact with medication. Avoid with thyroid medications. May cause photosensitivity in sensitive individuals.