Elaeagnus umbellata

Elaeagnus umbellata is known as Japanese silverberry,<ref name=NISI /> umbellata oleaster,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> autumn olive,<ref name=NISI /><ref name=GRIN>Template:GRIN</ref> autumn elaeagnus,<ref name=GRIN /> spreading oleaster,<ref name=GRIN /> autumnberry, or autumn berry. The species is indigenous to eastern Asia and ranges from the Himalayas eastwards to Japan. It is a hardy, aggressive invasive species able to readily colonize barren land, becoming a troublesome plant in the central and northeastern United States and Europe.<ref name="cabi">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Description

Elaeagnus umbellata grows as a deciduous shrub or small tree, typically up to Template:Convert tall, with a dense crown.<ref name=cabi/><ref name="parmar">Parmar, C. and M.K. Kaushal. 1982. Elaeagnus umbellata. p. 23–25. In: Wild Fruits. Kalyani Publishers, New Delhi, India. NewCROP, New Crop Resource Online Program, Purdue University</ref> It commonly bears sharp thorns in the form of spur branches.<ref name=parmar/> Flowers are fragrant, occur in clusters of white to yellow, are 8–9 mm in length and 7 mm in diameter, and have four lobes.<ref name=cabi/><ref name=parmar/>

The leaves are alternate, 4–10 cm long and 2–4 cm wide, with wavy margins. The leaves are covered with minute silvery scales when they emerge early in the spring<ref name=parmar/> but turn greener above as the scales wear off during the summer. The underside is more intensely covered in the silvery scales, differing from the related E. angustifolia, which remains silvery until it sheds its leaves in the fall.<ref name=cabi/>

Flowers

The flowers are borne in the leaf axils in clusters of 1–7. They are pale yellowish-white, fragrant, (often heavily fragrant) and have a four-lobed corolla 1 cm long.<ref name=cabi/> They are an important source of nectar for pollinators such as bees.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Fruit

The fruit is a small round drupe Template:Convert in diameter.<ref>Dirr, M. 1998. Manual of woody landscape plants : their identification, ornamental characteristics, culture, propagation and uses. Stipes, Champaign, Ill.</ref> The unripe fruit is silvery-scaled and yellow. It ripens to red, dotted with silver or brown. The ripe fruits are pulpy, juicy and sweet, 3–9 mm in length, 5 mm in diameter, and average 137 milligrams in weight, with a thin skin covering the whole fruit.<ref name="cabi" /><ref name="parmar" /> Having a sweet and tart flavor, the berries can be eaten fresh or processed for jam, condiments, flavoring, or used as a substitute for tomato.<ref name="usda">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> When mature, the red berries contain carotenoids, including considerable amounts of lycopene.<ref name="usda" />

Naturalization

In its origin regions of tropical and temperate Asia, E. umbellata is not considered to be an invasive species, but in many world regions, it has become invasive across wild and cultivated areas, particularly in the eastern United States.<ref name=cabi/> In the early 19th century, E. umbellata was purposely introduced to the U.S. and the United Kingdom for shelter belts, erosion control, wasteland reclamation, wildlife habitat, and for gardens as an ornamental.<ref name=cabi/> By the late 20th century, the shrub became a noxious weed and invasive species in many U.S. states from the east coast to the central prairies, and spread widely across Europe.<ref name=cabi/>

Due to its substantial seed production and avid germination potential, E. umbellata rapidly invades new areas where it can resprout readily after burning or cutting.<ref name=cabi/> Because E. umbellata stands are habitats for wildlife, such as providing forage and shelter for deer, nesting sites for birds, and berries as food for several species,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> it has been planted for wildlife management in parts of the U.S.<ref name=cabi/>

In Europe, E. umbellata has spread to the UK, Belgium, France, and Italy, but has been cultivated in the Netherlands and Scotland.<ref name=cabi/> In some parts of North America where it has become naturalized, E. umbellata is considered a noxious weed, particularly in the central and northeastern U.S.<ref name="cabi" /><ref name="NISI">Species Profile – Autumn Olive, National Invasive Species Information Center, National Agricultural Library. Lists general information and resources for Elaeagnus umbellata.</ref> In Canada, it is a "prohibited noxious weed" under the Alberta Weed Control Act 2010.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Because it fixes atmospheric nitrogen in its roots, E. umbellata may grow vigorously and sometimes competitively in infertile soils.<ref name=cabi/><ref>J.R. Clark, G.E. Hemery, and P.S. Savill. Early growth and form of common walnut (Juglans regia L.) in mixture with tree and shrub nurse species in southern England. Forestry (2008) 81 (5): 631-644 first published online September 5, 2008 doi:10.1093/forestry/cpn036</ref> It can increase available nitrogen in soils and benefit some nearby plants, and when grown in orchards, it can increase yields of adjacent fruit trees up to 10%.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> However, its ability to change soil chemistry can severely alter or destroy native plant communities.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Gallery

• Autumnolive2.JPG

  Leaves

• Honey bee foraging on Autumn Olive.jpg

  Blossoms

• Elaeagnus umbellata Frucht.jpg

  Ripe fruit

• Elaeagnus umbellata fruit.jpg

  Ripe fruit

• Elaeagnus umbellata leaf upper surface detail.jpg

  Leaf upperside

• Crop of Elaeagnus umbellata leaf upper surface detail.jpg

  Zoomed view

External links

• Template:Commons and category inline
• Elaeagnus umbellata images; Bioimages from Vanderbilt University, Nashville, TN, USA
• Species Profile - Autumn Olive (Elaeagnus umbellata), National Invasive Species Information Center, United States National Agricultural Library.