Buddleja davidii

Buddleja davidii
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Lamiales
Family:	Scrophulariaceae
Genus:	Buddleja
Species:	B. davidii
Binomial name
Buddleja davidii Franch.

Buddleja davidii (spelling variant Buddleia davidii), also called summer lilac, butterfly-bush, or orange eye, is a native of Sichuan and Hubei provinces in central China and of Japan. It is widely used as an ornamental plant, and many named varieties are in cultivation. B. davidii, named for the French explorer in China, Father Armand David, who first noticed the shrub, was found near Ichang by Dr Augustine Henry about 1887 and sent to St Petersburg. Another botanist-missionary in China, Jean André Soulié, provided seed to the French firm of nurserymen, Vilmorin, and B. davidii came on the Western market in the 1890s.

Description

B. davidii is a vigorous shrub with an arching habit, growing to 5 m in height. The pale brown bark becomes deeply fissured with age. The branches are quadrangular in section, the younger shoots covered in a dense indumentum. The opposite lanceolate leaves are 7 – 13 cm long, tomentose beneath when young. The honey-scented lilac to purple inflorescences are terminal panicles, < 20 cm long. Flowers are perfect (having both male and female parts), hence are hermaphrodite rather than monoecious (separate male and female flowers on the same plant) as is often incorrectly stated.

Varieties

Six varieties have been recognized:

var. alba Rehder & E.H.Wilson var. magnifica Rehder & E.H.Wilson var. nanhoensis Rehder

var. superba (de Corte) Rehder & E.H.Wilson var. veitchiana Rehder var. wilsonii Rehder

Cultivation

Buddleja davidii is appreciated in butterfly gardens for its value of its flowers as a nectar source for many species of butterflies.

There are in excess of one hundred cultivars as well as numerous hybrids with B. globosa and B. fallowiana grown in gardens. Many of these cultivars are of a dwarf habit growing to no more than 1.5 metres (4.9 ft).

This species is not able to survive the harsh winters of northern or montane climates, being killed by temperatures below about -15°C to -20°C (5° to -4°F). Even where it is not killed to the ground, in gardens it is generally partly stooled, with older shoots cut to the ground, as younger wood is more floriferous.

Invasive species

Buddleja davidii is naturalized in most cities of central and southern Europe, where it can spread on wastelands and in gardens. It can be an invasive species in many countries, including the United Kingdom and New Zealand. Within the United States, it is widely established as an escape from cultivation, and classified as a noxious weed by the states of Oregon and Washington.

References

• Van Laere K (2008) Interspecific hybridisation in woody ornamentals. PhD. Thesis, Faculty of Bioscience Engineering, Ghent University
• Christenhusz, M.J.M. (2009). Typification of ornamental plants: Buddleja davidii (Scrophulariaceae). Phytotaxa 2: 55-55.
• Franchet, M.A. (1887). Plantae Davidianae ex sinarum imperio, part 2 "Plantes du Thibet Oriental (Province de Moupine)". (Nouvelles Archives du Museum d'Histoire Naturelle Paris), ser. 2, 10: 33-198.
• Leeuwenberg, A.J.M. (1979). The Loganiaceae of Africa XVIII Buddleja L. II. Revision of the African and Asiatic species. Mededelingen Landbouwhogeschool Wageningen 79(6): 1-159.

See also

• Index: Buddleja — for Buddleja davidii cultivars.

External links

• Floridata: Buddleja davidii
• BBC Gardening: Buddleja davidii
• Pacific Island Ecosystems at Risk (PIER): Buddleja davidii
• USDA PLANTS Profile: Buddleja davidii
• RHS Buddleja Trials Report

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  Monarch Butterfly feeding on a buddleja flower, Connecticut, United States

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  Buddleja davidii flowers with Painted Lady, Peacock and (underneath) Small Tortoiseshell butterflies

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  Close-up of purple Buddleja davidii cultivar flowers