Magnolia L. (1753), the largest genus in the family Magnoliaceae, contains around 120 species, of which around 25 are hardy in cool temperate regions. Many species and hybrids are beautiful and popular garden trees and shrubs.

Description Trees to 30m in height, or shrubs, fast-growing in warm temperate climates. The leaves are deciduous or evergreen, alternate, usually ovate, not lobed, pinnately veined, and usually leaving a fine skeleton as they rot. Huge leaves to 60cm or more long are found in M. macrophylla Mich. in the southeastern United States. Winter buds are large, often with furry scales. The flowers are large, on the ends of the branches, often appearing in spring before the leaves, usually with 6–9 petals, but in some up to 33, in whorls of 3, white, pink, purple, or greenish, rarely yellow, usually scented. The stamens are numerous, spirally arranged, often with red filaments. Pollination is usually by beetles, which is common in primitive flowers, and also by honeybees, bumblebees, and flies. The fruits are often cone-like, with the seeds singly or in pairs, embedded in the receptacle. The seeds are suspended on thin threads, usually flattened, hard, and dark brown, with an orange or pink, fleshy aril.

Key Recognition Features Often huge flowers with whorls of smooth, fleshy petals, and numerous spirally arranged stamens and styles. Bark of the twigs usually aromatic, often lemon-scented.

Evolution and Relationships One of the most primitive genera of flowering plants; magnolia-like fossils from the mid-Cretaceous, called Archaeanthus, have been found in Dakota, Kansas. The simple stamens with pollen sacs on either side are a particularly primitive feature.

Ecology and Geography Magnolias are trees of moist forests. They are found in the northern hemisphere in eastern North America and Central America and in Asia ranging from the Himalayas to Japan and Sumatra.

Comment New yellow-flowered hybrids such as ‘Elizabeth’ are crosses between the green-flowered American M. acuminata L. and the white-flowered Chinese M. denudata Dersrouss. The timbers of some species are valued in Japan. The flowers of most species are edible, and the bark and flower buds of M. officinalis Rehd. & Wils. are used as a tonic in traditional Chinese medicine.