Fig. 6.1-4. Longitudinal section of axillary meristem of coleus (Coleus). At the top of the micrograph is the shoot apical meristem with two leaf primordia that are too young to have axillary meristems. Near the center of the micrograph is a leaf axil with a bulging axillary meristem. Its cells are stained dark red because the cells and vacuoles are so small that red-stained nuclei dominate the region. This axillary meristem is well-formed and will begin producing its own leaf primordia soon. Typically, the leaf primordia of axillary buds like this develop into bud scales that envelop and protect the axillary bud meristem (the meristem is called the "axillary meristem" while small like this, and the "axillary bud apical meristem" once there are some leaves and stem, that is, once it is obviously a bud).