Buddleja japonica is a deciduous

Deciduous

Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...

 shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

 native to Honshu

Honshu

is the largest island of Japan. The nation's main island, it is south of Hokkaido across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyushu across the Kanmon Strait...

 and Shikoku

Shikoku

is the smallest and least populous of the four main islands of Japan, located south of Honshū and east of the island of Kyūshū. Its ancient names include Iyo-no-futana-shima , Iyo-shima , and Futana-shima...

, Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, where it grows on mountain slopes amid scrub. The shrub was named and described by Hemsley

William Hemsley

William Hemsley may refer to:*William Hemsley , American planter, Continental Congressman from Maryland*William Hemsley , botanist...

 in 1889, and introduced to Western cultivation in 1896.

Description

B. japonica grows to < 1.5 m in height in the wild, open in habit and sparsely branched. The branches are tetragonous and winged. The leaves are narrowly lanceolate

Leaf shape

In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...

, < 20  cm long by < 5 cm wide, the upper surface dark green and glabrous, the underside tawny felted. The flowers form dense, drooping terminal panicles < 20 cm long, usually pale lilac in colour, from July to October. Overall, the species is considered of little horticultual merit, and is also comparatively shortlived.

Cultivation

In the UK a specimen is grown as part of the NCCPG national collection at Longstock Park

Longstock Park

Longstock Park is a country estate in the civil parish of Longstock in the Test Valley district of Hampshire, England. Formerly Longstock Manor, of medieval origins, it was purchased by Sir Joshua East in the nineteenth century. On his death, the estate passed to his sons Alfred and Arthur. In...

 Nursery, near Stockbridge

Stockbridge, Hampshire

Stockbridge is a small town and civil parish in Hampshire, England. It has an acreage of and a population of little under 600 people according to the 2001 census in Hampshire, England. It lies on the River Test, in the Test Valley district and renowned for trout fishing. The A30 road goes through...

, Hampshire

Hampshire

Hampshire is a county on the southern coast of England in the United Kingdom. The county town of Hampshire is Winchester, a historic cathedral city that was once the capital of England. Hampshire is notable for housing the original birthplaces of the Royal Navy, British Army, and Royal Air Force...

.

Varieties

B. japonica var. insignis, a plant with a more compact habit and more brightly coloured flowers.

Suppliers

The shrub is in commerce in the UK; vendors can be found in the RHS

Royal Horticultural Society

The Royal Horticultural Society was founded in 1804 in London, England as the Horticultural Society of London, and gained its present name in a Royal Charter granted in 1861 by Prince Albert...

's Plantfinder http://apps.rhs.org.uk/rhsplantfinder.