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Jai Ganesh

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Croton

Croton

Gist

Croton trees can reach a height of about 6 metres (20 feet), though varieties kept as houseplants can be significantly smaller. The plants are evergreen with brilliantly coloured, glossy, leathery leaves.

Summary

Croton (Codiaeum variegatum), colourful-leaved plant of the spurge family (Euphorbiaceae) native to Malaysia and the Pacific and extensively cultivated. Numerous horticultural varieties of shrubs or small trees have been developed, and the plant is commonly grown outdoors in pots or as a houseplant. As with many members of the family, croton sap can be irritating to the skin, and the plant is considered poisonous.

Croton trees can reach a height of about 6 metres (20 feet), though varieties kept as houseplants can be significantly smaller. The plants are evergreen with brilliantly coloured, glossy, leathery leaves. Leaf colours, mostly resulting from anthocyanin in the leaf, occur solid or in combinations of green, yellow, white, orange, pink, red, crimson, and purple. The 10–15-cm (4–6-inch) leaves vary from linear and lance-shaped to oval and lobed, depending on the variety. The plants can be propagated from stem cuttings.

Another plant of the same family, but of a different genus, is purging croton (Croton tiglium), a small tree; from its seeds, poisonous croton oil is extracted. It is native to Southeast Asia.

Details

Croton is an extensive plant genus in the spurge family, Euphorbiaceae. The plants of this genus were described and introduced to Europeans by Georg Eberhard Rumphius. The common names for this genus are rushfoil and croton, but the latter also refers to Codiaeum variegatum. The generic name comes from the Greek (krótos), which means "tick" and refers to the shape of the seeds of certain species.

Description

Croton is a diverse and complex taxonomic group of plants ranging from herbs and shrubs to trees. A well-known member of this genus is Croton tiglium, a shrub native to Southeast Asia. It was first mentioned in European literature by Cristóbal Acosta in 1578 as "lignum pavanae". The oil, used in herbal medicine as a violent purgative, is extracted from its seeds. Currently, it is considered unsafe and it is no longer listed in the pharmacopeias of many countries.

Uses:

Traditional uses

C. tiglium oil has been used in traditional Chinese medicine to treat severe constipation or heal lesions, and is used as a purgative. Wang Haogu first observed that croton seeds could also be used to treat diarrhea. It is a source of the organic compound phorbol and its tumor-promoting esters, such as 12-O-tetradecanoylphorbol-13-acetate. In the Amazon, the red latex from the species C. lechleri, known as sangre de drago (dragon's blood), is used as a "liquid bandage", as well as for other medicinal purposes, by native peoples.

Food uses

Cascarilla (C. eluteria) bark is used to flavour the liquor Campari and Vermouth.

Biofuel uses

In Kenya, Croton nuts, such as those from C. megalocarpus, were found to be a more economical source of biofuel than Jatropha curcas. Jatropha curcas requires as much as 20,000 litres of water to make a litre of biofuel, while Croton trees grow wild and yield about 35 percent oil. Croton trees are planted as a windbreak in Kenya, and their use as a source of biofuel may benefit rural economies there. As arable land is under population pressure, people have been cutting down the windbreaks to expand farmland. This new use may save the windbreaks, which should help fight desertification.

Ecology

Croton species are used as food plants by the larvae of some Lepidoptera species, including Schinia citrinellus, which feeds exclusively on the plant.

Distribution

The genus is pantropical, with some species extending into temperate areas. It is one of the largest and most complex genera of angiosperms in Madagascar, where up to 150 Croton species are endemic.

Additional Information

Croton, Codiaeum variegatum, is a common houseplant grown for its striking foliage. It is one of six species of broadleaf evergreen perennials, shrubs, and small trees in this genus in the euphorbia family (Euphorbiaceae) which are native to tropical Asia and the western Pacific region (not to be confused with Croton, another genus of more than 700 species in the same family, in which it was formerly incorrectly classified as Croton variegatum). This evergreen shrub or small tree varies widely in leaf color and pattern and numerous cultivars have been developed. It is a tender perennial, hardy only in zones 11-12. In subtropical and tropical climates they are frequently used as landscape shrubs for dramatic hedges, bold focal points in gardens, or potted specimens around buildings.

In its native habitat, croton is a branching, bushy shrub that grows up to 10 feet tall but those offered as houseplants are usually much smaller than the wild plant. The large, thick, leathery leaves are 2 to 12 inches long and quite variable. The shiny, alternate leaves may be linear to oval, have a smooth or lobed margin (sometimes deeply cut to the midrib), and some are wavy or twisted into a spiral. The foliage color ranges from green variegated with white, pink, orange, red, yellow, or purple in various combinations that may change as the leaves age. Markings may follow along the major veins or may be blotches on any part of the leaf blade in regular or random patterns. Sports, or shoots that are completely different in appearance from the parent plant, are not uncommon. As with most plants in the Euphorbiaceae, the milky sap that bleeds from cut stems may cause contact dermatitis in susceptible individuals.

When grown as a houseplant it rarely flowers. When growing in the ground in frost-free climates in spring it produces insignificant flowers in long axillary racemes. The white male flowers with five small petals and 20-30 stamens that give a starburst-like effect are produced on separate inflorescences than the yellowish, petal-less female flowers.

Pollinated female flowers are followed by fruits which are a small tripartite capsule about a third of an inch in diameter containing three small seeds.

Croton is typically offered as an indoor plant but can also be used outdoors as a seasonal accent plant in containers or plantings of annuals or mixed ornamentals. If growing in containers, indoors or out, think about choosing a pot color that accents the color of the foliage, either echoing one of the leaf colors or something that contrasts with the dominant color. Try combining croton with other tropical plants grown as annuals that have flowers in colors that repeat the color(s) of the leaves, such as orange-flowering lantana, yellow golden shrimp plant, or red pentas. Or choose something with purple flowers, such as angelonia or mealycup sage, to contrast with a croton cultivar with orange and red foliage.

Croton does best in fertile, well-drained, moist soil. They need bright, indirect light when grown indoors. Outdoors they thrive in partial shade, and in cool climates can tolerate full sun if kept moist (and are acclimated first when moved from inside). Higher light produces more vibrant color in the leaves and a more compact plant. The colorful leaves may revert to shades of green in insufficient light, while too much direct sun makes the leaves gray and dull looking. These plants have moderate water needs and should be watered only when the top half-inch to an inch of soil dries out. Reduce watering in the winter. Plants will drop leaves if they are too wet or too dry for extended periods. As a tropical plant, it does best with moderate to high humidity and warm temperatures.

Croton does best at temperatures between 60 and 85ºF, often suffering leaf drop if temperatures remain below 50ºF. Protect them from drafts and severe fluctuations in temperature. Changing environments too quickly can shock the plants and cause leaf drop. Fertilize once or twice during the growing season or more frequently if you want faster growth. Repot when the plant outgrows the container, moving up to a pot only 1-2 inches larger. Plants can be pruned hard in early spring before new growth begins to stimulate branching and new growth if they get leggy. Croton has few pest problems other than the usual insects that commonly infest houseplants (mealybugs, spider mites, scales).

Container-grown plants can be moved outdoors for the growing season once temperatures are consistently above 50ºF, gradually acclimating them to the different light levels outside and moving them back inside in the fall before temperatures drop below 50ºF (colder temperatures can cause leaf loss). Plants used as seasonal plants planted in the ground can be lifted and potted in the fall.
This plant is easily propagated by air layering in spring or by taking softwood cuttings in summer. Although it can be grown from seed, the offspring won’t resemble the parent, so asexual propagation is the only way to maintain specific cultivars.

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