Common Name: Camellia

General Information

Camellia japonica is an evergreen shrub or a small tree; it usually grows from 1.5 - 6 metres tall, occasionally reaching 11 metres[].
The plant is a valuable oil crop in parts of Asia and is commonly cultivated there. It is also widely used for its medicinal virtues. Camellia japonica is one of the most commonly grown ornamental plants, valued especially for its late winter to early summer display of flowers.
Camellia japonica has a wide range and is abundant. It is used extensively in horticulture, but is also harvested for food oil, medicine and dyes. The subpopulation from Japan is abundant, though there are known threats to the subpopulations in Taiwan and in the Republic of Korea, whilst it has been judged as rare in China. However, globally the plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

None known

Botanical References

, ,

Range

E. Asia - eastern China, central and southern Japan, Korea

Habitat

Woods in hills and down to sea level near the coast[]. Forests, at elevations from 300 - 1,100 metres[],

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	4.50 m
Growth Rate	Slow
Pollinators	Bees
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Camellia species are found mainly in the warm temperate to subtropical regions of southern China, and most species experience mild winters with few frosts plus wet summers[]. Camellia japonica is one of the hardiest members of the genus and has been reported to withstand temperatures down to lower than -30°c without damage[].
Species in this genus generally prefer a peaty, more or less lime-free soil with a pH in the range 5 - 7, but most will grow well in an open loam to which ample leaf-mould has been added, so long as it is well-drained and lime-free. Most species are understorey plants in forests (preferably oak or pine) and prefer a warm, sheltered position with moderate shade; at least at the hottest time of day[, ]. This species also grows well on a north-west aspect[] and against sunless walls[]. Requires a position sheltered from strong winds[]. Plants should be given a position shaded from the morning sun in order to protect the flowers from late frosts[].
A slow-growing plant[].
Plants are not very self-compatible, self-fertilized flowers produce few seeds and these are of low viability[].
A very ornamental plant[]. A large amount of named forms have been developed, mainly for their ornamental value[, ]. Many of the cultivars are able to tolerate full sun[, ].
Camellias are a valuable commercial crop in Asia, where they are cultivated for the oil obtained from their seed. Many of the cultivars grown in Britain do not set seed, unfortunately. The following cultivars have been seen with good crops of seeds:- 'Alba Simplex'; 'Coppelia'; 'Guillio Nuccio'; 'Jupiter'[].
The sub-species Camellia japonica macrocarpa. Masam has larger fruits than the type, looking like small apples[, ].
The sub-species Camellia japonica rusticana (Honda.)Kitamura. Is a hardier form of the species from northern Japan where it grows at higher elevations than the species and withstands long snowy winters[, ].

Edible Uses

An edible oil is obtained from the seed[, , , ]. It is called 'tsubaki oil'[]. Used mainly for cooking[].
The globose capsule is 25 - 45mm in diameter, 3-loculed with 1 or 2 brown, semiglobose to globose seeds 10 - 20mm in diameter per locule[].

Dried flowers - cooked[]. Used as a vegetable or mixed with gelatinous-rice to make a Japanese food called 'mochi'[, ].

The leaves are a tea substitute[, , , , ].

Medicinal

The flowers are astringent, antihaemorrhagic, haemostatic, salve and tonic[, ]. When mixed with sesame oil they are used in the treatment of burns and scalds[].

The oil is used medicinally[]. No further information is given, but the oil is likely to be used as an emollient on the skin[].

The plant has shown anticancer activity[].
The fruits contain various medicinally active compounds that have cytotoxic properties and are of potential use in the treatment of cancer[].
In other research, the plant has been shown to have antibacterial activity; to inhibit human immunodeficiency virus type 1 protease; to inhibit Epstein-Barr virus; to have antimetastasis activity; antioxidant activity; to inhibit human type
I procollagen production; to have an antiallergic response; and to be antiinflammatory[]

Other Uses

A green dye is obtained from the pink or red petals[].

Camellia japonica is used in crop breeding for Camellia sinensis for resistance to tea anthracnose, gray blight and cold damage. It is considered an important crop wild relative[].

A non-drying oil is obtained from the seed - used as a hair-dressing[, ]. A light oil, it can be used to lubricate fine machinert such as the moving parts of a watch[]. The oil consists mainly of oleic acid it is not subject to polymerize or oxidize, nor does it form solids at low temperatures[]. The oil can be used as a rust-preventing coating on metal[].

The oil obtained from the seed of this species is likely to be very similar in quality to that obtained from Camellia oleifera. The uses of that oil are as follows:-
The seed contains 40 - 50% of a non-drying oil. The oil consists mainly of oleic acid. It is not subject to polymerize nor to oxidize, nor does it form solids at low temperatures[]. The oil has a wide range of applications. It is a good raw material for industrial uses, it is used as an illuminant, in making textiles and in the manufacture of items such as soap, margarine, hair oil, lubricants, inks and paint. It is also used in the synthesis of other high-molecular weight compounds, and to make a rustproof coating for metals. It is often used medicinally and in cosmetics in items such as skin creams and anti-wrinkle compounds[, , , , , ].
Various compounds are extracted from the seeds once the oil has been removed. These include saponins (used an emulsifying agent in pesticides, for foam-forming fire extinguishers and in detergents), tannins and pentosan[].
The seed cake has insecticidal activity, and has been proven to give effective control over a range of pests[, ].

Propagation

Seed - can be sown as soon as it is ripe in a greenhouse[]. Stored seed should be pre-soaked for 24 hours in warm water and the hard covering around the micropyle should be filed down to leave a thin covering[, , ]. It usually germinates in 1 - 3 months at 23°c[]. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in light shade in the greenhouse for at least their first winter. Plant them out into their permanent positions when they are more than 15cm tall and give them some protection from winter cold for their first year or three outdoors[].
Cuttings of almost ripe wood, 10 - 15cm with a heel, mid summer to early autumn in a shaded frame. High percentage but slow[].
Cuttings of firm wood, 7 - 10cm with a heel, end of early summer in a frame[, ]. Keep in a cool greenhouse for the first year[].
Leaf-bud cuttings, mid summer in a frame.