The mustards constitute a family well marked in many ways. So much so that most people readily recognize mustards. The Cruciferae, as the mustards are technically known, are widely distributed but occur chiefly in temperate and northern regions. They are largely represented in the Mediterranean region. As understood by different authors, there are from 1200 to 2000 species.
Pammel, L. H.
"Some troublesome weeds of the mustard family.,"
Bulletin: Vol. 3
, Article 3.
Available at: https://lib.dr.iastate.edu/bulletin/vol3/iss34/3