Variegation is the appearance of differently coloured zones in the leaves and sometimes the
stems and fruit of plants. Species with variegated individuals are sometimes found in the
understory
In forestry and ecology, understory (American English), or understorey (Commonwealth English
The use of the English language in current and former member countries of the Commonwealth of Nations was largely inherited from British co ...
of
tropical rainforest
Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equatori ...
s, and this habitat is the source of a number of variegated houseplants. Variegation is caused by mutations that affect chlorophyll production or by viruses, such as
mosaic viruses, which have been studied by scientists. The striking look of variegated plants is desired by many gardeners, and some have deliberately tried to induce it for aesthetic purposes. There are a number of gardening books about variegated plants, and some gardening societies specialize in them.
The term is also sometimes used to refer to colour zonation in
flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism ...
s,
mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ...
s, and the skin, fur, feathers or scales of animals.
Causes
Chimeral
Because the variegation is due to the presence of two kinds of plant tissue, propagating the plant must be by a vegetative method of propagation that preserves both types of tissue in relation to each other.
Typically, stem
cuttings, bud and stem
grafting, and other propagation methods that results in growth from leaf axil buds will preserve variegation. Cuttings with complete variegation may be difficult, if not impossible, to propagate.
Root cuttings will not usually preserve variegation, since the new stem tissue is derived from a particular tissue type within the root.
Some variegation is due to visual effects caused by
reflection of light from the leaf surface. This can happen when an air layer is located just under the
epidermis
The epidermis is the outermost of the three l