Meristem
A
meristem is the tissue in most plants containing undifferentiated cells, found in zones of the plant where growth can take place. Meristematic cells give rise to various organs of the plant and keep the plant growing. The
shoot apical meristem gives rise to organs like the leaves and flowers, while the
root apical meristem provides the meristematic cells for the future root growth. SAM and RAM cells divide rapidly and are considered indeterminate, in that they do not possess any defined end status. In that sense, the meristematic cells are frequently compared to the stem cells in animals, which have an analogous behavior and function. The term
meristem was first used in 1858 by Karl Wilhelm von Nägeli in his book
Beiträge zur Wissenschaftlichen Botanik. It is derived from the Greek word
merizein, meaning to divide, in recognition of its inherent function. In general, differentiated plant cells cannot divide or produce cells of a different type.