Buddleia davidii (Loganiaceae)
This genus is named after the botanist and physician Adam Buddle and contains some 100 species native to the tropics and warmer temperate regions of America, Asia and South Africa. They are mostly shrubs, sometimes small trees or herbaceous plants. Buddleia davidii, the one most commonly cultivated, is a native of China. The leaves are opposite, thinly serrate, with stunted stipules. The , with bell-shaped calyx and trumpet-shaped corolla, are fragrant and borne in dense panicle from June to October. Because of their resemblance to sprays of lilac the shrub is often called the Himalayan or Tibetan lilac. It is a very variable species and there are many cultivars differing chiefly in the colour of the flowers. For example, ‘Empire Blue’ is blue, ‘Distinction’ dark violet, ‘Royal Red’ dark purple, and ‘White Bouquet’ pure white.
The botanical species are best increased by means of seed which should be sown immediately after being harvested. Cultivars are better propagated by softwood summer cuttings or hardwood cuttings. Young seedlings should be provided with a protective covering. Buddleias are best grown in light nourishing soils and in sunny situations. Older specimens are unsightly and can be cut back hard so that they will sprout new shoots from the base.
Buddleias are useful in gardens because they flower at a time when most trees and shrubs have already shed their blossoms. They are most striking planted in small groups.