The following information was gathered from various sources:
Is Thorny Olive Invasive?
– Learn How To Control Thorny Olive Plants
Elaeagnus pungens (Thorny Olive) is a species of the genus Elaeagnus found in North America. It is native to the Mediterranean region and other warm climates.
Its range extends into central Mexico, but it does not grow well there due to cold winters and hot summers. It prefers cooler temperatures and moist soil conditions.
In its natural habitat, it grows along streamsides and river banks. It forms dense stands up to several feet high with small green leaves that are oval in shape and very prickly when crushed or bruised.
The plants produce a large number of seeds that fall to the ground after they have been eaten by insects or birds. These seeds germinate quickly and begin growing roots within two weeks. They take three months before they reach maturity. When mature, the roots grow rapidly and form thickets of thorny vines that hang down from trees. The vine can reach over 10 feet long and wide.
The name “thorny” refers to the fact that these plants produce a large quantity of tiny white flowers at the base of their stems called petals which are covered with numerous little spikes or thorns. In addition to being prickly to the touch, it can also cause skin lesions.
It is a member of the olive family, and some people use the fruit for food. It is commonly grown as an ornamental plant due to its pretty flowers, dense growth habit, and suitability for hedges. It prefers full sun and well-draining sandy soil with a pH between 6.5 and 7.5. It can tolerate drought conditions once it is established.
Is Thorny Olive invasive?
Is the thorny olive an invasive plant?
It depends where you live. In its natural range in the Sonoran Desert, it grows in riparian zones, that is, near water such as wet stream beds and riverbanks. It can be found in other habitats, but it is most dominant along rivers and streams. In these areas, the thorny oleander can form a dense thicket, with trees completely covered in vines.
Its habitat is slowly expanding into neighboring regions of Arizona, due to global warming. It is currently found in South Texas, where it has grown from 17 square miles in 1996, to more than 1,700 square miles today.
This type of growth is typical for an invasive species.
What’s so bad about that?
When an invasive species takes over a new habitat, it can have devastating effects on native plants and animals. Native plants may be crowded out, or extincted altogether, depriving native animals of their natural food sources. For example, the bright red flowers of the thorny oleander are attractive to pollinators such as bees and butterflies. These insects can transport pollen from one plant to another, allowing for reproduction of the plant. In its natural range, it is pollinated by a native bee that is found in the Sonoran Desert and southern Texas. However, fire ants are also fond of the flower’s sugary fragrance.
Invasive populations of oleander are unable to reproduce due to a lack of the necessary pollinators. The ant also tends to protect its territory from any other insects that might pass through.
Without bees or butterflies to pollinate the flowers, the plants are unable to produce seeds. This is problematic because an oleander that cannot reproduce will not spread to new regions. As a result, new colonies are established by human intervention, and the species continues to crowd out native plants and harm animals that rely on them for food.
What’s being done about it?
The U.S. Fish and Wildlife Service has designated the thorny oleander as a noxious weed, making it illegal to transport or trade in the plant across state lines. Fines can be as high as $5,000.
Because thorny oleander is an attractive plant that attracts pollinators, there has been some commercial interest in cultivating it for agriculture and horticulture. The California Rare Fruit Growers have attempted to breed oleander varieties that are sterile, preventing the spread of this invasive plant.
So far, these experiments have been unsuccessful.
Invasive species are harmful to the environment because they can:
Out-compete native flora and fauna for resources.
Frequently prey on native animals.
Use up all available resources.
Prevent growth of native plants through competition for space and food.
Weedify! We don’t like that word, but it means to make something (or someone) wild and crazy.
Which is exactly what we like here at Scitable School!
Invasive species are a big problem, but the good news is there are simple things we can all do to help stop them!
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Until next time, remember: knowledge is power!
This episode of Scitable School is sponsored by the American Chemical Society.
Sources & references used in this article:
Russian-olive for wildlife and other conservation uses by AE Borell – 1971 – books.google.com
Challenges of predicting the potential distribution of a slow-spreading invader: a habitat suitability map for an invasive riparian tree by CS Jarnevich, LV Reynolds – Biological Invasions, 2011 – Springer
Natural history and invasion of Russian olive along eastern Montana rivers by P Lesica, S Miles – Western North American Naturalist, 2001 – JSTOR
Russian olive invasion into cottonwood forests along a regulated river in north-central Montana by P Lesica, S Miles – Canadian Journal of Botany, 1999 – NRC Research Press
Distribution and abundance of saltcedar and Russian olive in the western United States by PL Nagler, EP Glenn, CS Jarnevich… – … Reviews in Plant …, 2011 – Taylor & Francis