The Sacramento Bur (Triumfetta semitriloba), also known as burweed or burr bush, is a plant species in the mallow family (Malvaceae), known for its small sticky burs that attach to clothing and animal fur. It is native to tropical and subtropical regions of the Americas. The plant produces small, yellow flowers.Triumfetta semitriloba thrives in disturbed areas, such as roadsides and fields.