Common Name:

General Information

Camellia hongkongensis is an evergreen shrub or a tree; it can grow from 2 - 10 metres tall[].
The plant is sometimes harvested from the wild for its seed, which is the source of an oil. It is grown as an ornamental in gardens.
Camellia hongkongensis occurs in Hong Kong and on other coastal islands of China. The estimated extent of occurrence of this species is between 949-2,786 km2 and it is found in a maximum of four locations. Urbanisation, fruit tree plantations and felling for charcoal are all potential threats to this species and have been projected to cause a decline in the area and quality of habitat. The plant is classified as 'Endangered' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

None known

Botanical References

Range

E. Asia - southern China (Guangdong)

Habitat

Forests; at elevations from 200 - 300 metres[].

Properties

Conservation Status	Endangered
Edibility Rating
Habit	Evergreen Tree
Height	6.00 m
Cultivation Status	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 hongkongensis is found mainly at low elevations in southern China, and will only succeed outdoors in the very mildest regions of the temperate zone.
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[, ]. Requires a position sheltered from strong winds[].
This is a large red-flowered shrub or tree up to 10 metres tall growing in forests. It has limited cold hardiness, and in addition, the leaves are thought to be damaged by full sun-light. It is a slow growing evergreen tree. It prefers good soil near watercourses and between rocks[].
The plant has potential value for horticulture, as the hybrid combination between Camellia japonica and Camellia hongkongensis has showy red flowers[].

Edible Uses

An oil is obtained from the seed[].
The brown, globose to oblate capsule is 20 - 25mm x 25 - 35mm, 3-loculed with 1 or 2 brown, semiglobose to globose seeds around 10 - 15mm in diamseeds per locule[].

Medicinal

None known

Other Uses

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.