Camellia japonica

Camellia japonica, known as common camellia, or Japanese camellia, is a species of flowering plant in the family Theaceae. There are thousands of cultivars of C. japonica in cultivation, with many colors and forms of flowers. In the U.S. it is sometimes called japonica, a name more often used in the UK for Chaenomeles (flowering quince).

It can be found in the wild in China (Shandong, east Zhejiang), Taiwan and South Korea. It grows in forests, at altitudes of around 300-1,100 metres (980-3,610 ft).

This specis’ leaves are high in anti-inflammatory compounds such as lupeol or squalene.

Description

Camellia japonica is a flowering tree or shrub, usually 1.5-6 metres (4.9-19.7 ft) tall, but occasionally up to 11 metres (36 ft) tall. Some cultivated varieties achieve a size of 72 m² or more. The youngest branches are dark brown and become grayish as they age. The alternately arranged leathery leaves are dark green on the top side, paler on the underside, usually 5-11 centimetres (2.0-4.3 in) long by 2.5-6 centimetres (1.0-2.4 in) wide with a stalk (petiole) about 5-10 millimetres (0.2-0.4 in) long. The base of the leaf is pointed (cuneate), the margins are very finely toothed (serrulate) and the tip somewhat pointed.

In the wild, flowering is between January and March. The flowers are found along the branches, especially towards the ends. They have very short stems. They can be found alone or in pairs and measure 6-10 cm (2.4-3.9 inches) in diameter. There are nine sepals and bracteoles that are greenish. The wild flowers have six to seven white or rose petals. Each flower measures between 1.5 and 2.5 centimetres long (1.2-1.8 inches) and 1.5-2.5 centimetres wide (0.6-1.0 inches). The innermost petals can be joined at the base for upto a third of its length. Many cultivated varieties have more petals. The stamens measure 2.5-3.5 cm (1.0-1.4 inches) in length, with the outer whorl measuring 2.5-2.5 centimetres (1.0-1.48 inches). The three-lobed style is about 3 centimetres (1.2 in) long.

The fruit consists of a globe-shaped capsule with three compartments (locules), each with one or two large brown seeds with a diameter of 1-2 centimetres (0.4-0.8 in). In the wild, fruiting takes place in September and October.

C. japonica leaf are eaten by caterpillars of certain Lepidoptera such as the engrailed Ectropis Crepuscularia. The Japanese white-eyed bird ( Zosterops japonica), pollinates Camellia japonica.

Cultivation

Camellias should be planted in the shade in organic, somewhat acidic, semi-moist but well drained soil. If the soil is not well drained, it can cause the roots to rot.

As a Camellia species, C. japonica can be used to make tea. The aromatic aroma of the processed leaves is evident. It also contains catechins and caffeine of the same type as C. Sinensis.

Diseases

Some fungal and algal diseases include: Spot Disease, which gives the upper side of leaves a silver color and round spots, and can cause loss of leaves; Black Mold; Leaf Spot; Leaf Gall; Flower Blight, which causes flowers to become brown and fall; Root Rot; and Canker caused by the fungus Glomerella cingulata, which penetrates plants through wounds.
Some insects and pests of C. japonica are the Fuller Rose Beetle Pantomorus cervinus, the mealybugs Planococcus citri and Pseudococcus longispinus, the weevils Otiorhyncus salcatus and Otiorhyncus ovatus, and the tea scale Fiorinia theae.

Salt injury, which results in high salt levels in the soil, is one example of a physiological disease. Chlorosis, which is believed to be due to a lack of certain elements or insufficient acidity, prevents the roots from absorbing them; and bud drop, which is the loss or decay, can also be caused by high temperatures, over-watering, pot-bound roots, and high temperatures. Other diseases are oedema and sunburn. We don’t know much about viral diseases in C. japonica.

Taxonomy

The genus Camellia was named after a Jesuit priest and botanist named Georg Kamel. The specific epithet japonica was given to the species by Carl Linnaeus in 1753 because Engelbert Kaempfer was the first to give a description of the plant while in Japan.

In the Flora of China, there are two types: C. japonica and var. japonica, C.japonica are the two varieties. rusticana

Camellia japonica var. japonica

C. japonica var. japonica is the form named by Linnaeus, and naturally occurs in forests at altitudes of 300-1,100 metres (980-3,610 ft) in Shandong, eastern Zhejiang in mainland China and in Taiwan, south Japan, and South Korea. The stem (petiole), which is glabrous, measures approximately 1 cm (0.4 in). The bracteoles are velutinous (velvety) and the sepals. It flowers between January and March, and fruits in between September and October. It is grown as a garden plant in the form of many cultivars throughout the world.

Camellia japonica var. rusticana

Camellia japonica var. rusticana (Honda) T. L. Ming naturally occurs in forests in Zhejiang (island of Zhoushan Qundao) in mainland China and in Honshu, Japan. The leaf is approximately 5 millimetres long (0.2 in) and has fine pubescent hairs at its base. The bracteoles are smooth and the sepals are glabrous on the outside. The flowers are available in a variety of colors, including roses, pinks and reds. They bloom from April through May. This variety is regarded by some botanical authorities to be a separate species: Camellia rusticana.

In Japan it is known by the common name “yuki-tsubaki” (snow camellia) as it naturally occurs in areas of heavy snowfall at altitudes ranging from 1,100 metres (3,500 ft) down to 120 metres (400 ft) on sloping land under deciduous beech trees in the mountain regions to the north of the main island of Honshu and facing the Sea of Japan. The plants are covered by snow up to 2.4m (8ft) in December when heavy snowfalls from the north. From December to March, the snow covers the bushes until the snow melts in the early spring and the camellias begin flowering.

Cultivars of C. japonica var. rusticana includes: i>C. japonica/i> var. ‘Nishiki-kirin’,?Nishiki-no-mine’,?Toyo-no-hikari’ and?Otome’.