Seedling:  Seedlings: cotyledons are kidney or heart-shaped with indentation at tip, young leaves are elliptical with wavy margins.

Juvenile:  Young plants develop into a rosette

Mature:   Erect stems grow 1-3 feet tall from a basal rosette.  Upper leaves are toothed and have either a short petiole or none.  The upper leaves also clasp the stem, distinguishing this plant from other common mustards.  Lower leaves are deeply lobed and may be up to a foot long.  Above the upper seed, the pods have a obvious constricted beak.  Normally the entire plant is smooth.  The taproot resembles a small turnip.

Flowers:  Yellow flowers with 4 petals.  The plant flowers from May to August.

Life cycle:   winter annual or biennial

Reproduction is by seed. Seeds germinate in the early spring, summer, or fall. Seeds may remain viable in the soil for many years. One plant may produce over 1000 seeds.

Native of Europe.

Widespread throughout North America.

Also found along roadsides and waste areas.



Field Mustard


Brassica rapa 

from the link

an individual plant