Autumn olive

''Elaeagnus umbellata'' is known as Japanese silverberry, umbellata oleaster, autumn olive, autumn elaeagnus, spreading oleaster, 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.

Description

''Elaeagnus umbellata'' grows as a deciduous shrub or small tree, typically up to tall, with a dense crown.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. 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.

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 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.

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. They are an important source of nectar for pollinators such as bees.

Fruit

The fruit is a small round drupe in diameter. 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. 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. When mature, the red berries contain carotenoids, including considerable amounts of lycopene.

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. 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. 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.

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. 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, it has been planted for wildlife management in parts of the U.S.

In Europe, ''E. umbellata'' has spread to the UK, Belgium, France, and Italy, but has been cultivated in the Netherlands and Scotland. 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.Species Profile – Autumn Olive
National Invasive Species Information Center, National Agricultural Library. Lists general information and resources for ''Elaeagnus umbellata''. In Canada, it is a "prohibited noxious weed" under the ''Alberta Weed Control Act 2010''.

Because it fixes atmospheric nitrogen in its roots, ''E. umbellata'' may grow vigorously and sometimes competitively in infertile soils. 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%. However, its ability to change soil chemistry can severely alter or destroy native plant communities.

Gallery

File:Autumnolive2.JPG, Leaves
File:Honey bee foraging on Autumn Olive.jpg, Blossoms
File:Elaeagnus umbellata Frucht.jpg, Ripe fruit
File:Elaeagnus_umbellata_fruit.jpg, Ripe fruit
File:Elaeagnus umbellata leaf upper surface detail.jpg, Leaf upperside
File:Crop of Elaeagnus umbellata leaf upper surface detail.jpg, Zoomed view

References

External links

*
''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.

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