Source: Idaho's Noxious Weeds by Robert H. Callihan & Timothy W. Miller
BACKGROUND
Common crupina (Crupina vulgaris) is a native of the eastern Mediterranean region. Although it was introduced to North America (and first discovered in Idaho) less than 30 years ago, it has spread to over 60,000 acres in Idaho and moved into Oregon, Washington, and California. It is usually found on dry south slopes and pastures. It spreads by seed.
(Thumbnail linked to a larger photo)
DESCRIPTION
Common crupina is a winter annualPlant that germinates, flowers, seeds, and dies during one growing season that grows up to 4 feet in height. CotyledonsThe first leaflike structures that appear after germination; seed leaves (or seed leaves) exhibit a bright purple midribThe center and usually most prominent vein on a leaf. Leaves are simple and up to 6 inches long, entire near the base of the plant, lobed on the lower stem, and finely dissectedDeeply and repeatedly divided into smaller parts on the upper stem. Up to 5 narrow cylindrical seed heads are borne on the branch tips in midsummer. Flowers are pink to purple and are followed by dark seeds about the size of a kernel of wheat with a ring of black, bristly hairs at the point of attachment.
DISTRIBUTION
Common crupina is found exclusively in the Pacific Northwest and in central Idaho counties.
CONTROL
No biological control agents are available for common crupina, but herbicides are available that can control this weed.