Entry From
Flora of North America, Vol 7,
Names
Hirschfeldia incana (Linnaeus) Lagrèze-Fossat [family CRUCIFERAE], Fl. Tarn Garonne, 19. 1847
Sinapis incana Linnaeus [family CRUCIFERAE], Cent. Pl. I, 19. 1755
Brassica adpressa (Moench) Boissier [family CRUCIFERAE]
Brassica geniculata (Desfontaines) Ball [family CRUCIFERAE]
Hirschfeldia adpressa Moench [family CRUCIFERAE]
Sinapis geniculata Desfontaines [family CRUCIFERAE]
Discussion
Hirschfeldia incana was first collected in North America in 1895 in the San Bernardino region, and by 1936 it was described as “already a serious agricultural pest, spreading freely over dry, unbroken ground and flourishing chiefly during the arid summer season” (W. L. Jepson 1909–1943, vol. 2).
Hirschfeldia incana can be confused with Brassica nigra because both have fruits appressed to the rachis. The former is distinguished from the latter by its distinctly shorter fruit, seeded and often swollen beak, and smaller petals.