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small broomrape (Orobanche minor)
ODA rating: B
Oregon small broomrape distribution
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Images courtesy of Tom Forney, Oregon Dept. of Agriculture.
If images are downloaded and used from the ODA web site please be sure to credit the photographer.
Annual; blooms within a week of plant emergence. Grows 6 to 20 inches tall. Lacks chlorophyll; has yellowish-brown unbranched stem with purplish tint. Leaves look like small triangular scales. Flowers pinkish, yellow or white in color and arranged in an elongated terminal cluster.
Small broomrape is a parasitic plant. Upon germination, the first root attaches to and penetrates the root of the host plant, usually clover and other legumes, disrupting nutrients and water transport in the host root system. It has the ability to produce up to 500,000 seeds per plant that are dispersed by wind, tillage equipment, harvesters, commodity movement and animals. An uprooted flowering plant will continue to produce seed. Heavy infestations can cause severe crop damage that may result in nearly total crop failure. It is especially problematic in clover crops where the seeds are hard to detect or remove during inspections of harvested clover seed.
A European native, small broomrape was first documented in California in 1838. Small broomrape introduction routes are largely unknown, but likely involve contaminated crop seed and equipment.
Distribution in Oregon
The first documented site in Oregon was 1923 in Multnomah County.

Biological controls
No approved biological control agent is available.