United States, California, Butte, Old County Dump site, ne corner of jct of Humboldt Rd and Bruce Rd; ca. 3 mi e of downtown Chico. T22N R02E S29 NW corner USGS Quadrangle: Chico 1:24,000
Growing on the middens of the old dump site. Associates: Silybum marianum, Centaurea solstitialis, Erodium moschatum, E. cicutarium, Stellaria media, Hordeum leporinum, Bromus diandrus.
Voucher Specimen for "Studies in the Reproductive Biology of Mustard Species Occurring in Butte County, California"--R.E. Preston; Summer, 1983.