Primary Growth Points (Meristems) Of A Plant

We saw recently that root growth does not occur all over the surface of the roots, but is restricted to the meristems at the tips (hidden within the root cap for protection). Root extension then occurs in the regions just behind. The meristem at the tip of the main root is called an 'apical meristem'.

Similarly, we saw last year that a stem also has an apical meristem. If you remember, we removed this to create bushiness in our plants.

This removal released the dominance effect ('apical dominance'), created by this apical bud, on other meristems in the axillary buds in the leaf axils lower down the stem, allowing these to develop into side shoots.

As with roots, stem growth occurs in the regions just behind these meristems.

The meristems of a typical plant are shown here in green. As growers, we are very much concerned with these meristems, since they control the development of the plant.