Daisy. View of flowers and leaves of the daisy (Bellis perennis). The daisy is a very common plant which flowers from early spring through to late summer. As a medicinal herb, infusions of the flowers and leaves are used as mild sedatives, and may help insomniacs get to sleep. Extracts applied to fresh wounds help to prevent bruising, and can also soften the skin. Young leaves can be used in mixed salads to add flavour.