Elaeagnus

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Elaeagnus
Elaeagnus commutata USDA.jpg
American silverberry (Elaeagnus commutata)
Scientific classification e
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Rosales
Family: Elaeagnaceae
Genus: Elaeagnus
Tourn. ex L.[1]
Species

See text

Elaeagnus distribution.svg

Elaeagnus /ˌɛlˈæɡnəs/,[2] silverberry or oleaster, is a genus of about 50–70 species of flowering plants in the family Elaeagnaceae.[3]

Description[edit]

Elaeagnus plants are deciduous or evergreen shrubs or small trees.[3] The alternate leaves and the shoots are usually covered with tiny silvery to brownish scales, giving the plants a whitish to grey-brown colour from a distance. The flowers are small, with a four-lobed calyx and no petals; they are often fragrant. The fruit is a fleshy drupe containing a single seed; it is edible in many species. Several species are cultivated for their fruit, including E. angustifolia, E. umbellata, and E. multiflora (gumi). E. umbellata contains the carotenoid lycopene.[4]

Taxonomy[edit]

The genus Elaeagnus was erected in 1754 by Carl Linnaeus, who attributed the name to Joseph Pitton de Tournefort.[1][5] There is agreement that the name is based on Theophrastus's use of the Ancient Greek ἐλαίαγνος (elaíagnos, latinized to elaeagnus) as the name of a shrub.[6] The first part of the name, elae-, is from ἐλαία, 'olive'. Sources differ on the origin of the second part: it may be from ἂγνος, Vitex agnus-castus, the chaste tree,[6] or from the Greek name for a kind of willow.[7] In either case, the second part is derived from ἁγνός (hagnós), meaning 'pure', 'chaste'.[8]

Species[edit]

Elaeagnus comprises the following species:[9][10]

Species names with uncertain taxonomic status[edit]

The status of the following species is unresolved:[9]

  • Elaeagnus arakiana Koidz.
  • Elaeagnus asakawana Sa.Kurata
  • Elaeagnus attenuata Nakai
  • Elaeagnus crocea Nakai
  • Elaeagnus cyanea Aiton ex Steud.
  • Elaeagnus emarginata Colla
  • Elaeagnus fasciculata (Wall. ex Steud.) A.Nelson
  • Elaeagnus fragrans Nakai
  • Elaeagnus fruticosa (Lour.) A.Chev.
  • Elaeagnus fusca Pépin ex Lem.
  • Elaeagnus higoensis Nakai
  • Elaeagnus kiusiana Nakai
  • Elaeagnus laetevirens Lindb.
  • Elaeagnus latifolia Lour.
  • Elaeagnus mayeharai Nakai
  • Elaeagnus nagasakiana Nakai
  • Elaeagnus numajiriana Makino
  • Elaeagnus oleaster L.
  • Elaeagnus pauciflora C.Y. Chang (China)
  • Elaeagnus philippinensis Perrott. – lingaro berry (Philippines)
  • Elaeagnus × pyramidalis Browicz & Bugala (E. commutata × E. multiflora)
  • Elaeagnus oxycarpa Schltdl. (China)
  • Elaeagnus rotundifolia (Parry) A.Nelson
  • Elaeagnus sativa Dippel
  • Elaeagnus undulata auct.
  • Elaeagnus utilis A.Nelson
  • Elaeagnus veteris-castelli Lepage
  • Elaeagnus yakusimensis Masam.

Hybrids[edit]

The following hybrids have been described:[9][10]

  • Elaeagnus × maritima Koidz.
  • Elaeagnus × reflexa E.Morren & Decne. (E. pungens × E. glabra)
  • Elaeagnus × submacrophylla Servett. (E. macrophylla × E. pungens)

Habitat[edit]

The vast majority of the species are native to temperate and subtropical regions of Asia.[3] Elaeagnus triflora extends from Asia south into northeastern Australia, while E. commutata is native to North America, and Elaeagnus philippinensis is native to the Philippines. One of the Asian species, E. angustifolia, may also be native in southeasternmost Europe, though it may instead be an early human introduction there. Also, several Asiatic species of Elaeagnus have become established as introduced species in North America, with some of these species being considered invasive, or even designated as noxious, in portions of the United States.[3][11][12]

Ecology[edit]

Elaeagnus species are used as food plants by the larvae of some Lepidoptera species including Coleophora elaeagnisella and the Gothic moths. The thorny shrubs can also provide good nesting sites for birds.

Nitrogen fixation[edit]

Many Elaeagnus species harbor nitrogen-fixing organisms in their roots, so are able to grow well in low-nitrogen soils.[3] This ability results in multiple ecological consequences where these Elaeagnus species are present. They can become invasive in many locations where they are established as exotic species. Two species (E. pungens and E. umbellata) are currently rated as category II noxious, invasive species in many world regions[3] and by the Florida Exotic Pest Plant Council.[12]

Cultivation[edit]

Elaeagnus species are widely cultivated for their showy, often variegated, foliage, and numerous cultivars and hybrids have been developed.[13]

The fruit is acid and somewhat astringent.[3] It makes good tarts.[14]

E. angustifolia cultivated as bonsai

Notable species and hybrids in cultivation include:-

The hybrid Elaeagnus × submacrophylla[15] and the cultivar 'Gilt Edge'[16] have gained the Royal Horticultural Society's Award of Garden Merit.[17]

Berries from a large-fruited cultivar

References[edit]

  1. ^ a b "Elaeagnus Tourn. ex L." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 13 October 2021.
  2. ^ Sunset Western Garden Book. 1995. pp. 606–7. ISBN 978-0-376-03850-0.
  3. ^ a b c d e f g "Elaeagnus umbellata (autumn olive)". CABI. 3 January 2018. Retrieved 8 February 2018.
  4. ^ Fordham, Ingrid M.; Clevidence, Beverly A.; Wiley, Eugene R.; Zimmerman, Richard H. (2001). "Fruit of autumn olive : A rich source of lycopene". HortScience. 36 (6): 1136–7. ISSN 0018-5345.
  5. ^ Linnaeus, Carl (1754). "148. Elaeagnus". Genera Plantarum (5 ed.). Holmia (Stockholm): Laurentius Salvius. p. 57. Retrieved 13 October 2021.
  6. ^ a b Gilbert-Carter, H. (1955). Glossary of the British Flora (2nd ed.). Cambridge University Press. p. 30.
  7. ^ Johnson, A.T. & Smith, H.A. (1972). Plant Names Simplified : Their Pronunciation Derivation & Meaning. Buckenhill, Herefordshire: Landsmans Bookshop. p. 38. ISBN 978-0-900513-04-6.
  8. ^ Liddell, Henry George & Scott, Robert. "A Greek-English Lexicon". Perseus 4.0. Department of the Classics, Tufts University. Retrieved 13 October 2021.
  9. ^ a b c "The Plant List entry for Myrica". The Plant List, v.1.1. Royal Botanic Gardens, Kew and the Missouri Botanical Garden. September 2013. Retrieved 14 December 2020.
  10. ^ a b Govaerts R. "Myrica L." Plants of the World Online. Board of Trustees of the Royal Botanic Gardens, Kew. Retrieved 14 December 2020.
  11. ^ "Elaeagnus". County-level distribution maps from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014.
  12. ^ a b "Florida Exotic Pest Plant Council Invasive Plant Lists". Florida Exotic Pest Plant Council. Retrieved 6 February 2012.
  13. ^ RHS A-Z Encyclopedia of Garden Plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 1-4053-3296-4.
  14. ^ Maiden, J. H. (1889). The Useful Native Plants of Australia: Including Tasmania. Turner and Henderson, Sydney.
  15. ^ "RHS Plantfinder – Elaeagnus × submacrophylla". Retrieved 5 June 2020.
  16. ^ "Eleagnus × ebbengei 'Gilt Edge'". Royal Horticultural Society. Retrieved 5 June 2020.
  17. ^ "AGM Plants – Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 35. Retrieved 6 February 2018.

External links[edit]