<P> The growth of nitrogen fixing nodules on legume plants such as soybean and pea is either determinate or indeterminate . Thus, soybean (or bean and Lotus japonicus) produce determinate nodules (spherical), with a branched vascular system surrounding the central infected zone . Often, Rhizobium infected cells have only small vacuoles . In contrast, nodules on pea, clovers, and Medicago truncatula are indeterminate, to maintain (at least for some time) an active meristem that yields new cells for Rhizobium infection . Thus zones of maturity exist in the nodule . Infected cells usually possess a large vacuole . The plant vascular system is branched and peripheral . </P> <P> Under appropriate conditions, each shoot meristem can develop into a complete new plant or clone . Such new plants can be grown from shoot cuttings that contain an apical meristem . Root apical meristems are not readily cloned, however . This cloning is called asexual reproduction or vegetative reproduction and is widely practiced in horticulture to mass - produce plants of a desirable genotype . This process is also known as mericloning . </P> <P> Propagating through cuttings is another form of vegetative propagation that initiates root or shoot production from secondary meristematic cambial cells . This explains why basal' wounding' of shoot - borne cuttings often aids root formation . </P>

Which function is performed in the ground tissue of a plant but not in the meristematic tissue