field mustard
Family
BrassicaceaeScientific Name
Brassica rapa
Other Common Names:
wild mustard
birdsrape mustard
bird's rape
wild rutabaga
wild turnip
Habit
Plants germinate or sprout in fall, are green during the winter, and produce flowers and seed in the spring and early summer. Plants usually die back with summer heat. The stems are erect, 3 ft tall, branched, hairy, and usually bluish-green in color.
Leaves
Leaves are light to medium green, hairy or bristly, stalked, and are 12 to 20 in long. Like most mustards, leaves tend to feel rough due to the stiff hairs on the leaf surface. Leaves are often ravaged by insects and often appear with holes or eaten portions missing.
Identifying Characteristics
The flowers have four petals that form a cross.
Flower Seed Head
Flowers bright yellow; petals 6-10 mm long; those in maturity close together and commonly overtop the unopened buds; outer 2 stamens are much shorter than inner stamens.
Seed Fruit
Fruit is 1 1/2 to 2 1/2 in long with long tapering beak. Seeds are blackish or reddish-brown and 1.5-2 mm in diameter.
Where Found
Found along roadsides and waste areas. A common weed of agricultural fields
Growth Habit
upright and nonwoody
Thorns or Spines
not present
Approximate Flower Diameter
dime
Dominant Flower Color
yellow
Flower Symmetry
radial symmetery
Leaf Hairs
Varies:
has hairs,
no hairs
Leaf Shape
lance
Leaf Arrangement
alternate
Leaf Margin
Varies:
serrated,
wavy
Leaf Structure
simple
Leaf Stalk
none
Stem Hairs
no hairs
Stem Cross Section
round or oval
Milky Sap
not present
Root Structure
taproot
Life Cycle
biennial
Ochrea
not present
Plant Type
Herb