Actinidia

Actinidia /ˌæktɪˈnɪdiə/ is a genus of woody and, with a few exceptions, dioecious plants native to temperate eastern Asia, occurring throughout most of China, Taiwan, Korea, and Japan, and extending north to southern areas of Russian Far East and south into Indochina. The genus includes shrubs growing to 6 metres (20 feet) tall, and vigorous, strong-growing vines, growing up to 30 m (100 ft) in tree canopies. They mostly tolerate temperatures down to around −15 °C (5 °F), and some are much hardier.

Actinidia Temporal range: Middle Eocene–recent; 45–0 Mya PreꞒ Ꞓ O S D C P T J K Pg N
Actinidia kolomikta ('Arctic Beauty')
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Ericales
Family:	Actinidiaceae
Genus:	Actinidia Lindl.
Type species
Actinidia callosa  Lindl.

The leaves are alternate and simple, with a dentated margin and a long petiole. The flowers are solitary or in axillary cymes, usually white, with five small petals. Most of the species are dioecious with separate male and female plants, but some are monoecious. The fruit is a large berry containing numerous small seeds; in most species, the fruit is edible. In particular, this genus is known for the species Actinidia deliciosa, one of the most common cultivated kiwifruits, and for the hardy ornamental A. kolomikta.

Fossils of the extinct species A. faveolata are known from Europe and Western Siberia extending from the Upper Oligocene to the Early Pleistocene.

The 40–60 species of Actinidia include:

 

Kiwifruit is a cultivar group of A. deliciosa, and hardy kiwi is the species Actinidia arguta, which has small fruit weighing 10–15 g (0.35–0.53 oz), with green edible skins and green flesh; it is hardier than A. deliciosa. Some species are grown as ornamental plants, notably A. kolomikta.

In Japan, Actinidia polygama (silver vine) is noted for having an effect on cats much like that of catnip. It is mentioned in the saying 猫にまたたび、女郎に小判 (neko ni matatabi, jorō ni koban, "silver vine to a cat, a coin to a prostitute"), meaning to put someone in a good mood by providing that which they most desire.

A. kolomikta is the hardiest species (to about -40 °C or -40 °F), and has distinctive white- and pink-variegated foliage even on wild plants, an unusual phenomenon. Its fruit is very small, weighing 8 g (0.28 oz) or less.

Actinidia is derived from Ancient Greek ἀκτῑ́ς 'ray', and is a reference to the rayed styles of the flowers.