Sp. Pl. 1: 121. 1753.
Shrubs or trees, 5–10(–12) m, not clonal. Stems usually armed, with thornlike lateral branches, densely silvery-scaly when young, scales reddish brown in age, glabrate. Leaves deciduous (often tardily); blade lanceolate-linear to narrowly elliptic, 3–8(–10) × 0.5–1.5 cm, length 3–8 times width, surfaces silvery and densely stellate-hairy. Flowers solitary or 2 or 3 in clusters; hypanthium funnelform, 3.5–6 mm distal to constriction; calyx silver-green abaxially, yellow adaxially, 3–5 mm; nectary disc conspicuous, forming thick cylinders around styles. Fruits pale green, ovoid or ellipsoid, (8–)10–15(–20) mm, densely white-scaly and succulent, becoming dull orange-yellow and dry in age. 2n = 24, 28.
Phenology: Flowering May–Jul.
Habitat: Roadsides, along streams.
Elevation: 0–2000 m.
Introduced; Alta., B.C., Man., N.B., N.S., Ont., Que., Sask., Ariz., Calif., Colo., Conn., Del., D.C., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo., Eurasia.
Elaeagnus angustifolia was originally planted as an ornamental and as a windbreak and for erosion control; it has become weedy along waterways and in disturbed areas, especially in the western United States. The roots grow to great depths and, because the plants are heavy users of water, they are known to lower dramatically the water table. Russian olive is globally invasive and is spreading in arid regions. Where it lacks competition from other trees, it forms dense thickets that exclude most other vegetation.
The fruit is somewhat succulent when young but quickly becomes dry and mealy; it is sweet and edible, and is widely dispersed by birds. The plant is prone to diseases such as leaf spot, canker, rust, and Verticillum wilt in humid areas (M. A. Dirr 2009). Two varieties, var. angustifolia and var. orientalis (Linnaeus) Kuntze, have been recognized. The dried, powdered fruits are reportedly mixed with milk for the treatment of rheumatoid arthritis and joint pain.