Elaeagnaceae (oleaster) is one of the smaller plant families, with three genera (elaeagnus, hippophae, shepherdia) and, in the US, only nine species, out of a worldwide total of around 50. Five of the nine are non-native. Plants are shrubs or trees, often thorn-bearing, and they have small, simple leaves, covered by short, scale-like hairs. Radially-symmetric flowers form in small numbers from the leaf axils; they have four petal-like sepals, and four or eight stamens. The fruits resemble berries.