variegation

Variegation is the coloration pattern in which tissues of an organism exhibit multiple colors. In plants, it most often refers to leaves displaying patches of white or yellow tissue alongside green tissue, though variegation can affect stems and flowers. The white or pale areas reflect reduced or absent chlorophyll, while colored patches may derive from other pigments such as carotenoids or anthocyanins.

Causes and mechanisms: Variegation can arise through genetic mutations in nuclear DNA or in chloroplast genomes, through chimera formation where two genetically distinct cell lines occupy different parts of the plant, or through viral infection that produces mosaic patterns. In sectorial variegation, a meristem contains a chlorophyll-deficient sector that expands as the plant grows. Variegation can be inherited in some cultivars or arise spontaneously in cuttings or shoots.

Consequences and cultivation: Because pale tissues have limited photosynthesis, variegated plants typically grow more slowly and may be less tolerant of neglect. In cultivation, maintaining variegation often requires bright, indirect light and consistent nutrition. Some varieties revert to solid green if green sectors overtake the non-green sectors or under stress.

Other uses: Variegation also occurs in animals, notably in fur or plumage patterns such as calico cats or pied birds; in these cases, the pattern reflects genetic mosaicism or pigment cell distribution.