Sisymbrium altissimum L.
Family: Brassicaceae
tall tumble mustard
Sisymbrium altissimum image
Kitty Kohout  
Etymology: Sisymbrium: Greek name for some plant of the mustard family
Plants: erect, annual, 6"-40" tall forb, usually with many branches near the top
Leaves: stalked, pinnately-divided
Flowers: pale yellow, 4-parted, 1/2" wide; inflorescence a loose cluster (raceme) of stalked flowers; blooms June-July
Fruits: long, thin, erect pod on stalks almost as thick as the pod
Habitat: disturbed sites
Conservation Status: Introduced - naturalized