ginkgo

ginkgo or maidenhair tree, tall, slender, picturesque deciduous tree ( Ginkgo biloba ) with fan-shaped leaves. The ginkgo is native to E China, where it was revered by Buddhist monks and planted near temples. A "living fossil," the ginkgo is the only remaining species of a large order (Ginkgoales) of gymnosperms that existed in the Triassic period. Its form has not changed in millions of years, as is shown by fossils widely scattered over Europe, North and South America, and Asia. The ginkgo is valued today as a street tree, being exceptionally tolerant of smoke, low temperatures, and minimal water supply. The male and female strobile (see cone ) are borne on separate trees. The "fruit," botanically a seed, is surrounded by a malodorous pulp, making the male trees more desirable as ornamentals; however, the seed kernel is highly esteemed in East Asia as a food. The herbal remedy ginkgo biloba, an extract of ginkgo leaves, is said to enhance concentration and short-term memory. The ginkgo is classified in the division Pinophyta , class Ginkgoopsida, order Ginkgoales, family Ginkgoaceae.

Ginkgo A genus whose sole living member, G. biloba, is the maidenhair tree, native in China. It is deciduous, has leaves with open dichotomous venation, and is dioecious. The naked seed is oily and edible but the testa and embryo are bitter. It is widely cultivated. Many fossil species are known. G. digitata, the earliest representative of the genus, is first recorded from the Middle Jurassic and bears a close resemblance to its living relative. See GINKGOPHYTA.

ginkgo (maidenhair tree) Oldest living species of gymnosperm, native to temperate regions of China. It dates from the late Permian period. It has fan-shaped leaves, small, foul-smelling fruits and edible, nut-like seeds. Height: to 30m (100ft). Phylum Ginkgophyta; species Ginkgo biloba.