Elaeagnus

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

See text

Elaeagnus (/ˌɛlˈæɡnəs/)[2] is a genus of about 50–70 species of flowering plants in the family Elaeagnaceae.[3] Species of the genus are commonly known as silverberry or oleaster,

Description

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

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 ἄγνος, 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

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

  1. Elaeagnus angustata (Rehder) C.Y.Chang (China)
  2. Elaeagnus angustifolia L. – oleaster, Russian silverberry, or Russian olive (western Asia)
  3. Elaeagnus annamensis S.Moore
  4. Elaeagnus argyi H.Lév. (China)
  5. Elaeagnus bambusetorum Hand.-Mazz. (China)
  6. Elaeagnus bockii Diels (China)
  7. Elaeagnus bonii Lecomte
  8. Elaeagnus calcarea Z.R.Xu
  9. Elaeagnus caudata Schltdl. ex Momiy.
  10. Elaeagnus cinnamomifolia W.K.Hu & H.F.Chow (China)
  11. Elaeagnus commutata Bernh. ex Rydb. – American silverberry or wolf-willow (North America)
  12. Elaeagnus conferta Roxb. (southern Asia)
  13. Elaeagnus courtoisii Belval (China)
  14. Elaeagnus davidii Franch. (China)
  15. Elaeagnus delavayi Lecomte (China)
  16. Elaeagnus difficilis Servett. (China)
  17. Elaeagnus epitricha Momiy. ex H.Ohba
  18. Elaeagnus fasciculata Griff.
  19. Elaeagnus formosana Nakai (Taiwan)
  20. Elaeagnus formosensis Hatus.
  21. Elaeagnus geniculata D.Fang
  22. Elaeagnus glabra Thunb. (eastern Asia)
  23. Elaeagnus gonyanthes Benth. (China)
  24. Elaeagnus griffithii Servett. (China)
  25. Elaeagnus grijsii Hance (China)
  26. Elaeagnus guizhouensis C.Y.Chang (China)
  27. Elaeagnus henryi Warb. ex Diels (China)
  28. Elaeagnus heterophylla D.Fang & D.R.Liang
  29. Elaeagnus hunanensis C.J.Qi & Q.Z.Lin
  30. Elaeagnus indica Servett.
  31. Elaeagnus infundibularis Momiy.
  32. Elaeagnus jiangxiensis C.Y.Chang (China)
  33. Elaeagnus jingdonensis C.Y.Chang (China)
  34. Elaeagnus kanaii Momiy. (China)
  35. Elaeagnus lanceolata Warb. (China)
  36. Elaeagnus lanpingensis C.Y.Chang (China)
  37. Elaeagnus laosensis Lecomte
  38. Elaeagnus latifolia L. (southern Asia)
  39. Elaeagnus lipoensis Z.R.Xu
  40. Elaeagnus liuzhouensis C.Y.Chang (China)
  41. Elaeagnus longiloba C.Y.Chang (China)
  42. Elaeagnus loureiroi Champ. (southern China)
  43. Elaeagnus luoxiangensis C.Y.Chang (China)
  44. Elaeagnus luxiensis C.Y.Chang (China)
  45. Elaeagnus macrantha Rehder (China)
  46. Elaeagnus macrophylla Thunb. (eastern Asia)
  47. Elaeagnus magna (Servett.) Rehder (China)
  48. Elaeagnus matsunoana Makino
  49. Elaeagnus maximowiczii Servett.
  50. Elaeagnus micrantha C.Y.Chang (China)
  51. Elaeagnus mollis Diels (China)
  52. Elaeagnus montana Makino
  53. Elaeagnus morrisonensis Hayata (Taiwan)
  54. Elaeagnus multiflora Thunb. – cherry silverberry or gumi (eastern Asia)
  55. Elaeagnus murakamiana Makino
  56. Elaeagnus nanchuanensis C.Y.Chang (China)
  57. Elaeagnus obovata H.L.Li (China)
  58. Elaeagnus obovatifolia D.Fang
  59. Elaeagnus obtusa C.Y.Chang (China)
  60. Elaeagnus oldhamii Maxim. (China)
  61. Elaeagnus ovata Servett. (China)
  62. Elaeagnus pallidiflora C.Y.Chang (China)
  63. Elaeagnus parvifolia Wall. ex Royle (central Asia)
  64. Elaeagnus pilostyla C.Y.Chang (China)
  65. Elaeagnus pingnanensis C.Y.Chang (China)
  66. Elaeagnus pungens Thunb. – silverthorn (Japan)
  67. Elaeagnus pyriformis Hook.f. (eastern Himalaya)
  68. Elaeagnus retrostyla C.Y.Chang (China)
  69. Elaeagnus rhamnoides (L.) A.Nelson
  70. Elaeagnus rivularis Merr.
  71. Elaeagnus rotundata Nakai
  72. Elaeagnus sarmentosa Rehder (China)
  73. Elaeagnus schlechtendalii Servett. (China)
  74. Elaeagnus songarica Schltr.
  75. Elaeagnus s-stylata Z.R.Xu
  76. Elaeagnus stellipila Rehder (China)
  77. Elaeagnus takeshitai Makino
  78. Elaeagnus taliensis C.Y.Chang (China)
  79. Elaeagnus tarokoensis S.Y.Lu & Yuen P.Yang
  80. Elaeagnus thunbergii Servett. (China)
  81. Elaeagnus tonkinensis Servett. (southeastern Asia)
  82. Elaeagnus tricholepis Momiy.
  83. Elaeagnus triflora Roxb. (southeastern Asia, northeast Australia)
  84. Elaeagnus tubiflora C.Y.Chang (China)
  85. Elaeagnus tutcheri Dunn (southern China)
  86. Elaeagnus umbellata Thunb. – Japanese silverberry or autumn olive (eastern Asia)
  87. Elaeagnus viridis Servett. (China)
  88. Elaeagnus wenshanensis C.Y.Chang (China)
  89. Elaeagnus wilsonii H.L.Li (China)
  90. Elaeagnus wushanensis C.Y.Chang (China)
  91. Elaeagnus xichouensis C.Y.Chang (China)
  92. Elaeagnus xingwenensis C.Y.Chang
  93. Elaeagnus xizangensis C.Y.Chang (China)
  94. Elaeagnus yoshinoi Makino
  95. Elaeagnus yunnanensis Servett.

Species names with uncertain taxonomic status

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

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

Habitat

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

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

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

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

The fruit is acidic 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
Elaeagnus oldhamii

References

  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. Sunset Publishing Corporation. 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. doi:10.21273/HORTSCI.36.6.1136. 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. Archived from the original on 19 April 2021. Retrieved 6 February 2012.
  13. ^ RHS A-Z Encyclopedia of Garden Plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 978-1-4053-3296-5.
  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.