There is only one species in the genus. A deciduous tree growing to 40 m (130 ft.), it has lobed, fan-shaped leaves (similar in appearance to maidenhair fern foliage, but larger), which turn yellow in autumn. Flowering takes place after 20 years, with male and female flowers and fruits borne on separate trees. Male trees have an earlier leaf-fall and less spreading form; female fruits have a rancid smell when fallen. Ginkgo is a very robust tree and suffers from few pests, tolerates pollution well and a salty atmosphere.
History and traditions
Identical in appearance to tree fossils 200 million years old, ginkgo has always been a sacred tree in China it was grown for centuries in temples, some specimens reaching a great age, with circumferences up to 9 m (29 ft.). It has been cultivated in Europe since the early 18th century with seeds brought from China or Japan. The seeds have long been used in traditional Chinese medicine, and modern research has discovered constituents in the leaves of potential therapeutic importance, unknown in any other plant species.
Habitat/distribution
Originating in China and Japan, it is no longer found in the wild, but is cultivated as specimen and shade trees, and now widely grown in other countries.
Growth
Fully hardy, it does best in well-drained but fertile soil and a sunny position. Propagated from seed sown in containers in autumn or from cuttings taken in summer. It should not be pruned as this leads to die-back.
Parts used
Leaves picked in autumn and dried. Seeds used in decoctions.
Uses
Medicinal
The leaves have recently been discovered to contain compounds called ginkgolides, which promote blood flow, inhibit allergic reactions and have been found helpful for Parkinson’s disease. The seeds have antifungal and antibacterial properties, and are used in Chinese medicine for asthma and coughs.
Culinary
Ginkgo nuts (the female fruits with the outer unpleasant layer removed) are roasted and sometimes served with bird’s-nest soup in Chinese cuisine.
General
Seeds produce oil, which may cause dermatitis in sensitive people, and leaves contain insecticidal compounds.
