The classification of the genus Actinidia is difficult and the taxonomy of some taxa is still confusing. Various studies since 1984 have estimated the genus to comprise anywhere between 54 - 76 species. The species of Actinidia are highly variable in their vegetative structures, as well as in their flowers and fruits, which is the main reason for the difficulty in the classification of the genus. A detailed study of the genus, based on a wide range of specimens, is needed to clarify the situation and it could be many more years of work until a natural classification system is found - Xinwei LI, Jianqiang LI, Djaja Djendoel SOEJART; Advances in the study of the systematics of Actinidia Lindley; Front. Biol. China 2009, 4(1): pp 55 - 61.
The treatment followed here is based mainly on the Flora of China[], with some later amendments[].

Common Name:

General Information

Actinidia callosa is a vigorous, deciduous climbing shrub, producing stems up to 30 metres long that scramble over the ground and twine around the branches of other plants for support.
The plant is harvested from the wild for local use as a food. It is sometimes grown for its fruit and sometimes as an ornamental in gardens[, ].

Known Hazards

None known

Botanical References

, ,

Range

E. Asia - central and southern China, Taiwan, India, Nepal, Bhutan, Myanmar, Vietnam, Malaysia, Indonesia (Sumatra, Java).

Habitat

Forests, thickets, forest margins, valleys, slopes, streamsides and moist places at elevations of 400 - 2,600 metres in China[]. Mountain forests and forest borders at elevations of 1,000 - 2,040 metres in Malaysia[].

Properties

Edibility Rating
Habit	Deciduous Climber
Height	9.00 m
Pollinators	Bees, Insects
Self-fertile	No
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

A plant of the warm temperate to subtropical zones, entering into the tropics in Malaysia and Indonesia at elevations over 1,000 metres[]. It is found in montane areas of southern China where the climate is humid, the mean annual rainfall is in the range 1,300 - 2,000mm and summers are long and hot, with a long frost-free period of 270 - 300 days depending on elevation[]. It succeeds outdoors in the warmer regions of the temperate zone. Young spring growth is susceptible to frost damage[].
Prefers a sound loamy neutral soil[, ]. Succeeds in semi-shade but full sun is best for fruit production[]. Prefers a sheltered position[].
Fruits are formed on second year wood and also on fruit spurs on older wood[], any pruning is best carried out in the winter[].
There are some named varieties developed for their edible fruit[].
A polymorphic species, there are a number of sub-species[].
Plants in this genus are notably resistant to honey fungus[].
A dioecious species - both male and female forms must be grown if fruit and seed are required.
Female plants produce morphologically perfect flowers with well-developed pistils and stamens, but their stamens produce nonviable pollen; flowers of male plants have small, rudimentary ovaries without viable ovules but their stamens release viable pollen[].

Edible Uses

Fruit - raw or cooked[]. A very delicate flavour[, , , , ]. An acid flavour[]. The fruit can be dried for later use[]. The fruits are greyish-green when fully ripe and 18 - 50mm long[]. They contain a number of small seeds, but these are easily eaten with the fruit[].

Young shoots[].

Medicinal

None known

Other Uses

The wood is porous[].

Propagation

Seed - sow spring in a greenhouse[]. It is probably best if the seed is given 3 months stratification[], either sow it in a cold frame as soon as it is ripe in late autumn or as soon as it is received. Fresh seed germinates in 2 - 3 months at 10°c, stored seed can take longer[]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in light shade in the greenhouse for at least their first winter. When the plants are 30cm or more tall, plant them out into their permanent positions in late spring or early summer, after the last expected frosts[]. Most seedlings are male[]. The seedlings are subject to damping off, they must be kept well ventilated[].
Cuttings of softwood as soon as ready in spring in a frame[].
Cuttings of half-ripe wood, mid summer in a frame. Very high percentage[].
Cuttings of ripe wood, autumn in a frame.