Elaeagnus angustifolia
Elaeagnaceae
oleaster, olivier de bohême, Russian silverberry, Russian-olive
oleaster family
usually armed, with thornlike lateral branches, densely silvery-scaly when young, scales reddish brown in age, glabrate.
scurfy-pubescent, glabrate, or glabrescent [glabrous].
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.
deciduous or evergreen, opposite or alternate, simple;
stipules absent; petiolate or sessile;
blade membranous or leathery, venation pinnate, margins entire, surfaces pubescent, covered with silver, yellow, or rust scales, or stellate trichomes (sometimes glabrous adaxially in Elaeagnus multiflora).
axillary, racemes, spikes, umbels, or flowers paired or solitary;
bracts absent.
present or absent.
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.
bisexual or unisexual, actinomorphic;
perianth in 1 series, hypogynous;
hypanthium ± tubular, sometimes constricted, accrescent to pistil;
sepals 2 or 4, appearing as lobes on hypanthium, valvate, connate;
petals 0;
nectary disc well-developed or rudimentary;
stamens 4 or 8, filaments adnate to hypanthium, relatively short;
anthers basifixed or dorsifixed, dehiscing laterally, pollen colporate;
pistil 1-carpellate;
ovary superior, 1-locular;
placentation basal;
style 1, apical, slender;
stigma 1, capitate or linear;
ovule 1, anatropous, bitegmic.
pale green, ovoid or ellipsoid, (8–)10–15(–20) mm, densely white-scaly and succulent, becoming dull orange-yellow and dry in age.
achenes, covered by persistent and, sometimes, fleshy base of hypanthium, appearing drupe- or berrylike.
1 per fruit, oblong, ovoid, or ellipsoid;
embryo axile and centric, nearly filling testa;
endosperm scanty or absent.
= 24, 28.
Elaeagnus angustifolia
Elaeagnaceae
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.)
Genera 3, species ca. 45 (3 genera, 9 species in the flora).
All species of Elaeagnaceae have root nodules with nitrogen-fixing bacteria (Frankia). The capacity to fix nitrogen is advantageous to species colonizing disturbed habitats and may account, in part, for the occurrence of Russian olive (Elaeagnus angustifolia) as an invasive plant in parts of North America.
Some species of Elaeagnaceae that have been introduced into the horticulture trade have become weedy or problem exotics; see discussion under 1. Elaeagnus. Some species treated here have been reported as naturalized and caution should be used in selecting plants for landscape use; most Elaeagnaceae species have the potential to become weedy.
Phylogenetic trees based on chloroplast rbcL sequences group Elaeagnaceae and Rhamnaceae in the same clade (M. Clawson et al. 1998); no proposal has been made to combine the families. Some lines of evidence suggest a relationship with Rhamnaceae: wood anatomy and the presence of vestured pits (S. Jansen et al. 2000), DNA sequencing (J. E. Richardson et al. 2000), vegetative characteristics (R. F. Thorne 1992b), and the occurrence of nitrogen fixing symbioses in Elaeagnaceae and some Rhamnaceae, Rosaceae, and Ulmaceae (D. E. Soltis et al. 1995).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Flowers unisexual; plants dioecious; inflorescences appearing before leaves; leaves petiolate or sessile, alternate; calyces 2-lobed; hypanthia inconspicuous. | Hippophaë |
1. Flowers bisexual or unisexual; plants polygamous or dioecious; inflorescences usually appearing after leaves (except Shepherdia argentea); leaves petiolate, alternate or opposite; calyces 4-lobed; hypanthia conspicuous. | → 2 |
2. Leaves alternate; pedicels present; flowers bisexual; plants polygamous; stamens 4. | Elaeagnus |
2. Leaves opposite; pedicels absent; flowers unisexual; plants dioecious; stamens 8. | Shepherdia |
27. Stems subglabrous, often matted, 8–30(–40) cm; leaf blades broadly elliptic proximally, narrowly elliptic or lanceolate to sublinear distally. | E. oregonense |
27. Stems densely glandular puberulent, loosely clumped, 5–20 cm; leaf blades broadly obovate to orbiculate proximally to ovate or lanceolate distally. | E. howellii |
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WildflowerSearch
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- Local floras: CA, OR
- Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria
- WildflowerSearch
- iNaturalist (observations)
- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
