Elaeagnus L. (1753), in the family Elaeagnaceae, contains around 40 species around the northern hemisphere. Description Trees to 7m, or shrubs, sometimes climbing and with spines. The leaves are alternate, evergreen or deciduous, simple, often silvery and scaly beneath. The flowers are solitary or in small clusters, white or yellowish, usually scented. Sepals 4, equal, joined at the base to form a tube; petals absent. Stamens 4, on the throat of the tube, alternating with the sepals. Ovary superior, with 1 carpel containing 1 ovule; style 1, with an elongated stigma. Pollination is by bees. The fruits are mealy or fleshy and juicy berries, with 1 stone-like seed. Key Recognition Features The silvery, scaly, or hairy back of the simple leaves and the small, 4-lobed, scented flowers. Daphne has similar flowers but never has scaly leaves. Evolution and Relationships In flower and in the 1-seeded fruit the Eleagnaceae is similar to the Thymeliaceae, which includes the familiar Daphne. It is here associated with the southern-hemisphere Proteaceae with which it has in common the lack of petals and the single carpel, but the Proteaceae has diversified into a large number of remarkable shrubs, especially in Australia and South Africa. DNA evidence, however, now suggests that Eleagnaceae is closer to families such as Rhamnaceae and Ulmaceae, in the order Rosales. Ecology and Geography In open habitats and semi-deserts, and in scrub in the mountains; many species can exploit poor soils because of their nitrogen-fixing root nodules containing actinomycetes. Elaeagnus is found from eastern Europe across Asia to Japan and North America. Comment Many species are cultivated for their scented flowers and attractive, silvery leaves; the scent of the early summer-flowering E. angustifolia L., sometimes called Russian olive, is especially arousing. The species E. macrophylla Thunb. and E. pungens Thunb. from Japan and their hybrid E. x ebbingii Boom are popular evergreens, their cultivars often having variegated leaves, small flowers with a sharp, penetrating scent in autumn, and juicy, reddish berries in spring. Photographs:
Elaeagnus macrophylla fruit
Elaeagnus angustifolia at Adelaide Botanic Garden |
