St John's Wort is a perennial herb that blossoms in tight bouquets of yellow flowers. It grows in abundance next to old walling and in forest clearings. It acquired its botanical name because its perforated leaves secrete hypercin through many small holes. In the Middle Ages, it was reputed to have numerous virtues, ranging from exorcising demons to soothing asthma. Recent studies have shown that it also has anti-depressant properties. The oil extracted from St John‘s Wort is valued in cosmetology chiefly for its moisturising effects.