Photo Credit
Photo courtesy of ©1995 Saint Mary's College of California.

Field mustard

Scientific name
Brassica rapa
Also Known As
Common mustard
Plant Family
Plant Group
Field mustard is a 1 to 3 ft herb (sometimes shrub) with leaves that have 3 to 5 lobes and small, bright yellow 4-petaled flowers borne on branched flowering stems.
Identification Hints

Field mustard is a 1 to 3 ft herb (sometimes shrub) with leaves that have 3 to 5 lobes and small, bright yellow 4-petaled flowers borne on branched flowering stems.

Did You Know?

This species is native to Europe, but it has become widespread in the United States. This is the plant from which turnips and turnip greens are produced commercially.

Leaves
Leaves are light to medium green, with hairs. Leaf length is variable 11 to 20 in (30 to 50 cm). The lower leaves have 3 to 5 deep lobes along their margins (edges). The basal and lower stem leaves are attached directly to the stem, and you will often see the base of the leaves surrounding the stem where they attach to it. The leaf margins are often so deeply lobed that they almost appear to be made up of individual leaflets.
Flowers
Sally and Andy Wasowski, Lady Bird Wildflower Center, www.wildflower.org
Fruits
Each flower develops into an elongated fruit that becomes 1 to 2.75 in (3 to 7 cm) long when ripe. Fruits are dry, with a long, tapering beak (hook). Seeds are released when the fruit opens, and are dark brown to black.
Habitat
Fields of cereals, orchards and disturbed fields and roadsides at elevations less than 5000 ft (1500 m). Widespread and weedy.
Bloom Time
January to May
States
AK, AL, AR, AZ, CA, CO, CT, DE, FL, GA, HI, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NV, NY, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VA, VT, WA, WI, WV, WY