genus of Parnassus, in botany; a genus of the tetragynia order, belonging to the pentandria clas of plants. The calyx is quinquepartite; there are five petals, and as many nectaria, heart-shaped, and ciliated with globular tops; the capsule quadrivalved. There is but one species, having a stalk about a foot high, angular, and often a little twisted, bearing a single white flower at top. The flowers are very beautifully streaked with yellow; so that though it is a common plant, growing naturally in moist pastures, it is frequently admitted into gardens.