Meristem is the region marked by presence of active cell growth and the tissues present in meristem are termed as meristematic tissues. On the basis of their position in plant body, meristems are grouped as apical, lateral or intercalary meristem. Secondary growth is caused by lateral meristem. A flower is defined as condensed shoot and is derived from shoot apical meristem by the process of specialization of leaves into floral appendages. Leaf is green, exogenous, lateral outgrowth which develops from shoot apical meristem. Fruit is a ripened ovary which serves to protect the ripening ovule. Thus, flower, leaf and ovary develop from primary meristem and lack any lateral meristem that causes secondary growth, i.e., these structures mainly have primary tissues. Stem and roots have inter- and intra-fascicular cambium which is a lateral meristem (secondary) and produce secondary stelar (secondary xylem and phloem) and extra stelar tissues (phelloderm, phellogen and phellem). Shoot and root tip have apical meristem.