The most common form of variegation among dicotyledons is white around the edge or margin of a leaf, and for a monocotyledonous leaf , striped is a common form . In both monocotyledons and dicotyledons, one can find handsome variegated forms in which the principal veins are lacking pigments because cells above and below the conducting tissues of the veins are not involved in photosynthesis. Variegation is also observed occasionally on stems. The stripes are vertical because cell divisions for stem elongation of these grasses occur just above each node, in dividing cells called an intercalary meristem. If a portion of that meristem has cells lacking the ability to make chlorophyll, then all cells derived from and above those cells will have the same defect.
Variegated leaves are freaks, but they are truly freaks of nature.
Especially in the tropics one can find species with variegated leaves. Horticulturists brought these species into cultivation , and in greenhouses and nurseries people have also searched through their stocks for spontaneous mutants. Because white patches on leaves are not photosynthetic, we should not expect nor do we find that variegated forms grow as vigorously as do nonvariegated forms under identical conditions. Variegated forms are also sensitive to damage by intense sunlight. This explains much about how these plants are used in landscaping.