A field weed, some strains of which are important vegetables and fodder crops, the Old World origins lost in antiquity. Found in disturbed ground, such as railroad ballast, fields, and roadsides. First collected in 1884 in Kent and Keweenaw Cos.

The foliage is usually completely glabrous, although sometimes there are stiff translucent hairs on the lower leaves, especially on the midrib beneath and the margins.