The tip of the lilac stem

experiment 26 cloves stem tipLilac stem tip and root, mainly composed of sub-living
tissue
, the top sub-living tissue continuously cell division and differentiation to form the above-ground part of the plant. The tip of the stem is different from the tip of the root, there is no cap-like structure on the outside, but is tightly wrapped in many young leaves. From the permanent production of the vertical cutting surface of the tip of the lilac stem, it can be seen that the wide cone with a slight protrusion in the center is the primary tissue, the base of which has a symmetrical pair of small protrusions, is the leaf original base, the closer these protrusions are to the base, which is the formation process of the young leaves. The small protrusions in the leaves of the young leaves are the root of the buds, and in the permanent production it can be seen that the buds have formed in the leaves of the larger leaves of the base (Figure 26-1).Beneath the primary tissue is the primary sub-tissue, where cells have begun to differentiate into the primary cortical layer, the primary formation layer, and the basic sub-living tissue. Unlike the root's primary tissue, the original formation layer is scattered in a bundle in the basic sething tissue and arranged in a circle.cells produced by primary tissue continue to grow and differentiate, elongated along the vertical axis of the stem, forming elongated regions. The elonged area of the stem is much longer than the elonged area of the root.the outer elongation area is the mature zone, when the original formation layer bundle has developed into a dimensional beam, consisting of the primary wood part, the primary ligament part and the formation layer in the beam.The origin ofleaves and buds is different from the internal origin of the side roots, they are formed by the formation of the second and third layer of cells at the base of the leaf or bud protrusion, at the same time, the protruding surface layer of the cells around the division, so called the outer origin.