PURPLE LOOSESTRIFE, in botany: A genus of the monogynia order, belonging to the decandria class of plants; and in the natural method ranking under the 17th order, Calycanthemæ. The calyx is cleft in 12 parts; and there are six petals inserted into it; the capsule is bilocular and polyspermous. There are 10 species, of which the most remarkable are, 1. The falcaria, or common purple loosestrife, with oblong leaves, is a native of Britain, and grows naturally by the sides of ditches and rivers. It hath a perennial root, from which come forth several upright angular stalks, rising from three to four feet high, garnished with oblong leaves placed sometimes by pairs; but sometimes there are three leaves at each joint standing round the stalk. The flowers are purple, and produced in a long spike at the top of the stalk; so make a fine appearance. 2. The hypanum, or Spanish loosestrife, with an hyssop leaf, grows naturally in Spain and Portugal. It hath a perennial root. The stalks are slender, not more than nine or ten inches long, spreading out on every side. The lower part of the stalks is garnished Lyttelton, with oblong oval leaves placed opposite. The flowers come out singly from the side of the stalks at each joint; they are larger than those of the common sort, and make a fine appearance in the month of July when they are in beauty. The first kind is propagated by parting the roots in autumn, but requires a moist soil—the second is propagated by seeds brought from those countries where it is native.