leafy spurge (Euphorbia esula)
ODA rating: B and T
Description
Leafy spurge is an upright, branching, perennial herb two-three feet tall. It has alternate narrow leaves, somewhat frosted and slightly wavy along the margins. The flower of this weed are very small and are borne in greenish-yellow structures surrounded by yellow distinctive heart-shaped bracts.
Impacts
Leafy spurge is one of the West's worst weed species because it reduces cattle carrying capacity of infested rangelands by 50 to 75%. Once established, control of even modest-sized infestations is difficult, and annual treatments are required to contain populations. A grazing prescription which includes sheep grazing prior to other livestock has been sucessful in increasing agricultural productivity in rangelands infested with leafy spurge in parts of the West. This weed tolerates moist to dry soil conditions but is most common under dry conditions with coarse-textured soils where competition from native plants is reduced. It is capable of invading disturbed sites, including prairies, savannas, pastures, abandoned fields and roadside areas.
Click on image to view larger photo
|
|
Images courtesy of Dan Sharratt, Oregon Department of Agriculture
|
|
If images are downloaded and used from the ODA web site please be sure to credit the photographer.
Known hazards
A milky latex exists in all parts of the plant that can cause skin irritations in humans, cattle, and horses and may cause permanent blindness if rubbed into the eye.
Introduction
Native to Europe and Asia, brought to the U. S. from Eurasia about 1897 and it now occurs across much of the northern states including Pacific Northwest.
Distribution in Oregon
First report of this plant in Oregon was 1930 in Klamath County.
Map legend
Yellow: limited distribution
Red: abundant
Grey: not known to be present
Biological controls
There are twelve approved biological control agents available, six of which have been established in Oregon.
Apthona lacertosa
Informational Links
WeedMapper
|
