FNA: Elaeagnus angustifolia vs. Elaeagnus

Phenology

Flowering May–Jul.

Habitat

Roadsides, along streams.

Elevation

0–2000 m. (0–6600 ft.)

Distribution

AZ; CA; CO; CT; DC; DE; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NS; ON; QC; SK; Eurasia [Introduced in North America]

[WildflowerSearch map]

[BONAP county map]

North America; Eurasia; Australia

[BONAP county map]

Discussion

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.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Species ca. 45 (5 in the flora).

The flowers of Elaeagnus are strongly sweet-scented with a fragrance that most people find pleasant; the fruits are generally edible and attractive to birds. Some Eurasian species have been introduced into the horticulture trade and are now naturalized in North America (M. A. Dirr 2009). Some of these species have the potential to hybridize with native species; E. angustifolia, E. pungens, and E. umbellata have become noxious weeds. New introductions should be carefully considered and monitored.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key

1. Shrubs or trees 2–10(–12) m; leaves deciduous, blade surfaces densely silver or silver-green, (sometimes less densely so or with scattered, brown scales abaxially).	→ 2
2. Leaf blades ovate-oblong or elliptic (lengths 2 times widths); nectary discs incon- spicuous; stems unarmed, scales gray in age.	E. commutata
2. Leaf blades lanceolate-linear to narrowly elliptic (lengths 3–8 times widths); nectary discs conspicuous; stems usually armed, with thornlike lateral branches, scales reddish brown in age.	E. angustifolia
1. Shrubs or trees 1–5 m; leaves deciduous or evergreen, blade surfaces silvery or silver-green abaxially, silver-green or green adaxially.	→ 3
3. Stems armed; leaves evergreen, blades leathery, margins wavy, surfaces with silver scales, more densely hairy and silvery-green abaxially, glabrous and lustrous dark green or dull silver-green adaxially; petioles woody.	E. pungens
3. Stems usually unarmed (young ones thornlike in E. umbellata); leaves deciduous, blades not leathery, margins entire or ± wavy, surfaces silvery abaxially (sometimes with scattered, brown scales), green or dark green and sparsely pubescent or glabrous adaxially; petioles not woody.	→ 4
4. Flowers solitary or paired, hypanthium broadly flared, calyx lobes with brown scales outside; leaf blades 1–2.5(–5) cm, broadly lanceolate or cuneate.	E. multiflora
4. Flowers densely clustered, hypanthium narrowly funnelform, calyx lobes with silver scales outside; leaf blades (2–)3–8(–10) cm, elliptic or ovate.	E. umbellata