Camellia is a genus of flowering plants in the familyTheaceae. They are found in eastern and southern Asia, from the Himalayas east to Japan and Indonesia. There are 100–300 described species, with a few controversy over the exact number. There are additionally around 3,000 hybrids. The genus was named by Linnaeus after the Jesuit botanist Georg Joseph Kamel, who worked in the Philippines and described a species of camellia (although Linnaeus didn't refer to Kamel's account when discussing the genus). Camellias are famous throughout East Asia; they're known as cháhuā (茶花) in Chinese, "tea flower", an apt designation, as tsubaki (椿) in Japanese, as dongbaek-kkot (동백꽃) in Korean and as hoa trà or hoa chè in Vietnamese.

Of economic importance in the Indian subcontinent and Asia, leaves of C. sinensis are processed to create the popular beverage, tea. The ornamental C. japonica, C. sasanqua and their hybrids are the source of hundreds of garden cultivars. C. oleifera produces tea seed oil, used in cooking.

Description

Camellias are evergreenshrubs or small trees up to 20 m (66 ft) tall. Their leaves are alternately arranged, simple, thick, serrated, and usually glossy. Their flowers are usually large and conspicuous, one to 12 cm in diameter, with five to nine petals in naturally occurring species of camellias. The colours of the flowers vary from white through pink colours to red; truly yellow flowers are found only in South China and Vietnam. Camellia flowers throughout the genus are characterised by a dense bouquet of conspicuous yellow stamens, often contrasting with the petal colors. The so-called "fruit" of camellia plants is a dry capsule, at times subdivided in up to five compartments, each compartment containing up to eight seeds.

The various species of camellia plants are generally well-adapted to acidic soils rich in humus, and most species don't grow well on chalky soil or additional calcium-rich soils. Most species of camellias additionally require a large amount of water, either from natural rainfall or from irrigation, and the plants won't tolerate droughts. Notwithstanding a few of the more unusual camellias – typically species from karst soils in Vietnam – can grow without too much water.

Camellia plants usually have a rapid growth rate. Typically they'll grow about 30 cm per year until mature – though this does vary depending on their variety and geographical location.

Camellia plants are used as food plants by the larvae of a number of Lepidoptera species; see List of Lepidoptera that feed on Camellia. Leaves of the Japanese camellia (C. japonica) are susceptible to the fungalparasiteMycelia sterile (see for the significance).

Use by humans

Camellia reticulata is rare in the wild but has been cultivated for hundreds of years.

Camellia sinensis, the tea plant, is of major commercial importance because tea is made from its leaves. The species C. sinensis is the product of a large number of generations of selective breeding in order to bring out qualities considered desirable for tea. Notwithstanding a large number of additional camellias can be used to produce a similar beverage. For example, in a few parts of Japan, tea made from C. sasanqua leaves is popular.

Tea oil is a sweet seasoning and cooking oil made by pressing the seeds of C. oleifera, C. japonica, and to a lesser extent additional species such as C. crapnelliana, C. reticulata, C. sasanqua and C. sinensis. Relatively little-known outside East Asia, it is the most important cooking oil for hundreds of millions of people, particularly in southern China.

Camellia oil is commonly used to clean and protect the blades of cutting instruments.

Camellia oil pressed from seeds of C. japonica, additionally called tsubaki oil or tsubaki-abura (椿油) in Japanese, has been traditionally used in Japan for hair care.

Ecology

The camellia parasiteMycelia sterile produces a metabolite named PF1022A. This is used to produce emodepside, an anthelminticdrug.

Mainly due to habitat destruction, several camellias have become quite rare in their natural range. One of these is the aforementioned C. reticulata, grown commercially in thousands for horticulture and oil production, but rare enough in its natural range to be considered a threatened species.

Garden history

Camellia amplexicaulis in Hải Phòng, Việt Nam
Camellia flower close up

Camellias were cultivated in the gardens of China and Japan for centuries before they were seen in Europe. The German botanist Engelbert Kaempfer reported that the "Japan Rose", as he called it grew wild in woodland and hedgerow, but that a large number of superior varieties had been selected for gardens. He was told that the plant had 900 names in Japanese. Europeans' earliest views of camellias must have been their representations in Chinese painted wallpapers, where they were often represented growing in porcelain pots.

The first living camellias seen in England were a single red and a single white, grown and flowered in his garden at Thorndon Hall, Essex, by Robert James, Lord Petre, among the keenest gardeners of his generation, in 1739. His gardener James Gordon was the first to introduce camellias to commerce, from the nurseries he established after Lord Petre's untimely death in 1743, at Mile End, Essex, near London.

With the expansion of the tea trade in the later eighteenth century, new varieties began to be seen in England, imported through the British East India Company. The Company's John Slater was responsible for the first of the new camellias, double ones, in white and a striped red, imported in 1792. Further camellias imported in the East Indiamen were associated with the patrons whose gardeners grew them: a double red for Sir Robert Preston in 1794 and the pale pink named "Lady Hume's Blush" for Amelia, the lady of Sir Abraham Hume of Wormleybury, Hertfordshire (1806). The camellia was imported from England to America in 1797 when Colonel John Stevens brought the flower as part of an effort to grow attractions within Elysian Fields in Hoboken, New Jersey. By 1819, twenty-five camellias had bloomed in England; that year the first monograph appeared, Samuel Curtis's, A Monograph on the Genus Camellia, whose five handsome folio coloured illustrations have usually been removed from the slender text and framed. Camellias that set seed, though they didn't flower for more than a decade, rewarded their growers with a wealth of new varieties. By the 1840s, the camellia was at the height of its fashion as the luxury flower. The Parisian courtesan Marie Duplessis, who died young in 1847, inspired Dumas' La Dame aux camélias and Verdi's La Traviata.

The fashionable imbricated formality of prized camellias was an element in their decline, replaced by the new hothouse orchid. Their revival after World War I as woodland shrubs for mild climates has been paralleled by the rise in popularity of Camellia sasanqua.

Modern cultivars

Today camellias are grown as ornamental plants for their flowers; about 3,000 cultivars and hybrids have been selected, a large number of with double or semi-double flowers. C. japonica is the most prominent species in cultivation, with over 2,000 named cultivars. Next are C. reticulata with over 400 named cultivars, and C. sasanqua with over 300 named cultivars. Popular hybrids include C. × hiemalis (C. japonica × C. sasanqua) and C. × williamsii (C. japonica × Camellia saluenensis|C. saluenensis). Some varieties can grow to a considerable size, up to 100m², though more compact cultivars are available. They are frequently planted in woodland settings, alongside additional calcifuges such as rhododendrons, and are particularly associated with areas of high soil acidity, such as Cornwall and Devon in the UK. They are highly valued for their quite early flowering, often among the first flowers to seem in the late winter. Late frosts can damage the flower buds, resulting in misshapen flowers.

There is great variety of flower forms:

  • single (flat, bowl- or cup-shaped)
  • semi-double (rows of large outer petals, with the centre comprising mixed petals and stamens)
  • double:
    • paeony form (convex mass of irregular petals and petaloids with hidden stamens)
    • anemone form (one or more rows of outer petals, with mixed petaloids and stamens in the centre)
    • rose form (overlapping petals showing stamens in a concave centre when open)
    • formal double (rows of overlapping petals with hidden stamens)

The following hybrid cultivars have gained the Royal Horticultural Society's Award of Garden Merit:

NameParentageSizeFlower colourFlower typeRef.
Cornish Snowcuspidata × saluenensis04.0m²whitesingle
Cornish Springcuspidata × japonica04.0m²pinksingle
Francie Lreticulata × saluenensis64.0m²rose-pinkdouble
Freedom Bell× williamsii06.5m²redsemi-double
Inspirationreticulata × saluenensis10.0m²rose-pinksemi-double
Leonard Messelreticulata × saluenensis16.0m²rose-pinksemi-double
Royaltyjaponica × reticulata01.0m²light redsemi-double
Spring Festival× williamsii, cuspidata10.0m²pinksemi-double
Tom Knudsenjaponica × reticulata06.3m²deep reddouble paeony
Tristrem Carlyonreticulata10.0m²rose pinkdouble paeony

Selected species

Camellia fraterna
Flower buds of an unspecified camellia
Fruits of an unspecified camellia
Camellia japonica - MHNT

Cultural significance

Portrait of a New Zealand suffragette, circa 1880. The sitter wears a white camellia, symbolic of support for advancing women's rights.

The Camellia family of plants in popular culture.