Problem 31

Background and context

Primary growth in plants is governed by the apical meristems that cause an increase in the length of the stem and roots. Secondary growth in plants is governed by the lateral meristems that increase the girth of the plant. Secondary growth is absent in herbaceous plants and is common in woody plants. The lateral tissues responsible for secondary growth are the vascular cambium and the cork cambium. The vascular cambium is located between the primary xylem and primary phloem. The cells of the vascular cambium divide to form the secondary xylem and secondary phloem. The cork cambium forms the tough, outermost layer of the stem and is present in the bark of the woody plant.