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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 of tropical rainforests, and this habitat is the source of a number of variegated houseplants. [1] 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 flowers, minerals, and the skin, fur, feathers or scales of animals.
Plants that are chimeras contain tissues with more than one genotype. A variegated chimera contains some tissues that produce chlorophyll and other tissues which do not. [2] 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 resulting in a white or silvery reflection. It is sometimes called blister variegation. Pilea cadierei (aluminum plant) is an example of a house plant that shows this effect. Leaves of most Cyclamen species show such patterned variegation, varying between plants, but consistent within each plant. Another type of reflective variegation is caused by hairs on parts of the leaf, which may be coloured differently from the leaf. This is found in various Begonia species and garden hybrids.
Sometimes venal variegation occurs – the veins of the leaf are picked out in white or yellow. This is due to lack of green tissue above the veins. It can be seen in some aroids. The blessed milk thistle, Silybum marianum, is a plant in which another type of venal variegation occurs, but in this case it is due to a blister variegation occurring along the veins.
A common cause of variegation is the masking of green pigment by other pigments, such as anthocyanins. This often extends to the whole leaf, causing it to be reddish or purplish. On some plants however, consistent zonal markings occur; such as on some clovers, bromeliads, certain Pelargonium and Oxalis species. On others, such as the commonly grown forms of Coleus, the variegation can vary widely within a population. In Nymphaea lotus , the tiger lotus, leaf variegations appear under intense illumination.
Virus infections may cause patterning to appear on the leaf surface. The patterning is often characteristic of the infection. Examples are the mosaic viruses, which produce a mosaic-type effect on the leaf surface or the citrus variegation virus (CVV). Recently[ when? ] a virus disease, Hosta virus X (HVX) has been identified that causes mottled leaf coloring in hostas. At first, diseased plants were propagated and grown for their mottled foliage, at the risk of infecting other healthy hostas. [3] While these diseases are usually serious enough that the gardener would not grow affected plants, there are a few affected plants that can survive indefinitely, and are attractive enough to be grown for ornament; e.g. some variegated Abutilon varieties. Nutrient deficiency symptoms may cause a temporary or variable yellowing in specific zones on the leaf. Iron and magnesium deficiencies are common causes of this. Transposable elements can cause colour variegation. [4]
It has been suggested that some patterns of leaf variegation may be part of a defensive "masquerade strategy." [5] In this, leaf variegation may appear to a leaf mining insect that the leaf is already infested, and this may reduce parasitization of the leaf by leaf miners. [6]
By convention, the italicised term variegata as the second part of the Latin binomial name, indicates a species found in the wild with variegation ( Aloe variegata ). The much more common, non-italicised, inclusion of 'Variegata' as the third element of a name indicates a variegated cultivar of an unvariegated parent ( Aucuba japonica 'Variegata'). However, not all variegated plants have this Latin tag, for instance many cultivars of Pelargonium have some zonal variegation in their leaves. Other types of variegation may be indicated, e.g. Daphne odora 'Aureomarginata' has yellow edging on its leaves.
Variegated plants have long been valued by gardeners, as the usually lighter-coloured variegation can 'lift' what would otherwise be blocks of solid green foliage. Many gardening societies have specialist variegated plants groups, such as the Hardy Plant Society's Variegated Plant Special Interest Group in the UK. Several gardening books which deal exclusively with variegated plants are available.
In 2020, a variegated Rhaphidophora tetrasperma plant sold at auction for US$5,300. [7] In June 2021, another variegated Rhaphidophora tetrasperma plant sold at auction for US$19,297. [8]
Epipremnum aureum is a species in the arum family Araceae, native to Mo'orea in the Society Islands of French Polynesia. The species is a popular houseplant in temperate regions but has also become naturalised in tropical and sub-tropical forests worldwide, including northern South Africa, Australia, Southeast Asia, South Asia, the Pacific Islands and the West Indies, where it has caused severe ecological damage in some cases.
A genetic chimerism or chimera is a single organism composed of cells with more than one distinct genotype. In animals and human chimeras, this means an individual derived from two or more zygotes, which can include possessing blood cells of different blood types, and subtle variations in form (phenotype). Animal chimeras are produced by the merger of two embryos. In plant chimeras, however, the distinct types of tissue may originate from the same zygote, and the difference is often due to mutation during ordinary cell division. Normally, genetic chimerism is not visible on casual inspection; however, it has been detected in the course of proving parentage. In contrast, an individual where each cell contains genetic material from two organisms of different breeds, varieties, species or genera is called a hybrid.
Vegetative reproduction is a form of asexual reproduction occurring in plants in which a new plant grows from a fragment or cutting of the parent plant or specialized reproductive structures, which are sometimes called vegetative propagules.
Pelargonium is a genus of flowering plants that includes about 280 species of perennials, succulents, and shrubs, commonly called geraniums, pelargoniums, or storksbills. Geranium is also the botanical name and common name of a separate genus of related plants, also known as cranesbills. Both genera belong to the family Geraniaceae. Carl Linnaeus originally included all the species in one genus, Geranium, and they were later separated into two genera by Charles Louis L'Héritier de Brutelle in 1789.
Hosta is a genus of plants commonly known as hostas, plantain lilies and occasionally by the Japanese name gibōshi. Hostas are widely cultivated as shade-tolerant foliage plants. The genus is currently placed in the family Asparagaceae, subfamily Agavoideae, and is native to northeast Asia. Like many "lilioid monocots", the genus was once classified in the Liliaceae. The genus was named by Austrian botanist Leopold Trattinnick in 1812, in honor of the Austrian botanist Nicholas Thomas Host. In 1817, the generic name Funkia was used by German botanist Kurt Sprengel in honor of Heinrich Christian Funck, a collector of ferns and alpines; this was later used as a common name and can be found in some older literature.
A plant cutting is a piece of a plant that is used in horticulture for vegetative (asexual) propagation. A piece of the stem or root of the source plant is placed in a suitable medium such as moist soil. If the conditions are suitable, the plant piece will begin to grow as a new plant independent of the parent, a process known as striking. A stem cutting produces new roots, and a root cutting produces new stems. Some plants can be grown from leaf pieces, called leaf cuttings, which produce both stems and roots. The scions used in grafting are also called cuttings.
Aglaonema is a genus of flowering plants in the arum family, Araceae. They are native to tropical and subtropical regions of Asia and New Guinea. They are known commonly as Chinese evergreens.
Dracaena reflexa is a tree native to Mozambique, Madagascar, Mauritius, and other nearby islands of the Indian Ocean. It is widely grown as an ornamental plant and houseplant, valued for its richly coloured, evergreen leaves, and thick, irregular stems.
Fatsia japonica, also fatsi, paperplant, false castor oil plant, or Japanese aralia, is a species of flowering plant in the family Araliaceae, native to southern Japan and southern Korea.
The Field Elm cultivar Ulmus minor 'Atinia Variegata', the Variegated-leaved common English Elm, formerly known as U. procera 'Argenteo-Variegata' and described by Weston (1770) as U. campestris argenteo-variegata, is believed to have originated in England in the seventeenth century and to have been cultivated since the eighteenth. The Oxford botanist Robert Plot mentioned in a 1677 Flora a variegated elm in Dorset, where English Elm is the common field elm. Elwes and Henry (1913) had no doubt that the cultivar was of English origin, "as it agrees with the English Elm in all its essential characters". At the Dominion Arboretum, Ottawa, the tree was listed as U. procera 'Marginata', as the variegation is sometimes most obvious on leaf-margins.
The Field Elm cultivar Ulmus minor 'Argenteo-Variegata' or simply 'Variegata', known in Australasia and North America as Silver Elm or Tartan Elm, is said to have been cultivated in France from 1772. Green noted that variegated forms of Field Elm "arise frequently, and several clones may have been known under this name". Dumont de Courset (1802) listed an U. campestris var. glabra variegata, Loudon (1838) an U. nitens var. variegata, and Wesmael (1863) an U. campestris var. nuda microphylla variegata.
The Field Elm cultivar Ulmus minor 'Viminalis Pulverulenta' (:'powdery'), also known as 'Viminalis Variegata', a variegated form of U. minor 'Viminalis', was first mentioned by Dieck, in 1885 as U. scabra viminalis pulverulentaHort., but without description. Nursery, arboretum, and herbarium specimens confirm that this cultivar was sometimes regarded as synonymous with U. minor 'Viminalis Marginata', first listed in 1864, which is variegated mostly on the leaf margin. It is likely, however, that 'Pulverulenta' was the U. 'Viminalis Variegata', Variegated Twiggy-branched elm, that was listed and described by John Frederick Wood, F.H.S., in The Midland Florist and Suburban Horticulturist 1847 and 1851, pre-dating both Kirchner and Dieck. Wood did not specify the nature of the variegation.
Coleus scutellarioides, commonly known as coleus, is a species of flowering plant in the family Lamiaceae, native to southeast Asia through to Australia. Typically growing to 60–75 cm (24–30 in) tall and wide, it is a bushy, woody-based evergreen perennial, widely grown for the highly decorative variegated leaves found in cultivated varieties. Another common name is painted nettle, reflecting its relationship to deadnettles, which are in the same family. The synonyms Coleus blumei, Plectranthus scutellarioides and Solenostemon scutellarioides are also widely used for this species.
Pilea peperomioides, the Chinese money plant, UFO plant, pancake plant, lefse plant or missionary plant, is a species of flowering plant in the nettle family Urticaceae, native to Yunnan and Sichuan provinces in southern China.
Hakonechloa is a genus of bunchgrass in the tribe Molinieae of the grass family, Poaceae, native to eastern Asia.
Aucuba japonica, commonly called spotted laurel, Japanese laurel, Japanese aucuba or gold dust plant (U.S.), is a shrub native to rich forest soils of moist valleys, thickets, by streams and near shaded moist rocks in China, Korea, and Japan. This is the species of Aucuba commonly seen in gardens - often in variegated form. The leaves are opposite, broad lanceolate, 5–8 cm (2.0–3.1 in) long and 2–5 cm (0.79–1.97 in) wide. Aucuba japonica are dioecious. The flowers are small, 4–8 mm (0.16–0.31 in) diameter, each with four purplish-brown petals; they are produced in clusters of 10-30 in a loose cyme. The fruit is a red drupe approximately 1 cm (0.39 in) in diameter that is avoided by birds.
Peperomia obtusifolia, also known as the baby rubberplant, American rubber plant, or pepper face, is a species of flowering plant in the genus Peperomia under the family Piperaceae, native to Florida, Mexico and the Caribbean. The specific epithet obtusifolia means "blunt-leaved". The plant has gained the Royal Horticultural Society's Award of Garden Merit.
Abutilon mosaic virus (AbMV) is a virus of the genus Begomovirus. It infects Abutilon species, notably the flowering maple, Abutilon striatum. The mottled or variegated effect on the leaves of Abutilon striatum is sought after.
Crassula ovata, commonly known as jade plant, lucky plant, money plant or money tree, is a succulent plant with small pink or white flowers that is native to the KwaZulu-Natal and Eastern Cape provinces of South Africa, and Mozambique; it is common as a houseplant worldwide. Much of its popularity stems from the low levels of care needed; the jade plant requires little water and can survive in most indoor conditions. It is sometimes referred to as the money tree; however, Pachira aquatica also has this nickname.
Rhaphidophora pertusa is a climbing species of aroid plant within the genus Rhaphidophora of the Araceae family. The species—which, superficially, is quite similar to R. tetrasperma—is found on the Andaman-Nicobar Islands and the Maldives, as well as in Bangladesh, India, Myanmar, Thailand and Sri Lanka.