herbaceous plant, plant whose stem is soft and green and shows little growth of wood. The term is used to distinguish such plants from woody plants. Herbaceous plants, or herbs, as they are commonly called, may be annual—that is, the plants die after a year's growth, and the plants are propagated by seed—or they may be produced each year by new shoots from dormant roots. The stems of woody plants, e.g., most shrubs and trees, are tough, are covered with nongreen bark, and enlarge in diameter by the accumulation of annual layers of wood produced by the cambium.