Alliaria petiolata (M. Bieb.) Cavara & Grande (= Alliaria officinalis Andrz. ex Bieb.) garlic mustard, alliare officinale
Self-incompatible winter annual or biennial herb; erect; flowers white; locally common in the east, but rare in the west; occurs along roadsides, in open woods and near early European settlements. It can become an invasive plant in semi-shaded and shaded habitats. Cows eating garlic mustard can produce milk with a disagreeable flavor. Originally introduced from Europe for use as a medicinal and salad plant.
Barbarea vulgaris W.T.Aiton, yellow rocket, barbarée vulgaire
Biennial or short-lived perennial, spreading mostly by seeds;
allogamous; stems to 2 feet (6 dm.) high; flowers yellow, one of
the first weeds to flower in the spring; throughout our area,
but particularly common in the eastern part of our range; mostly
in non-cultivated fields, roadsides and waste places; introduced
from Europe.
Berteroa incana (L.) DC., hoary alyssum, bertéroa blanc
Annual or winter annual herb; semi-erect; flowers white. Sporadic, but locally abundant, especially on poorer soils. Occurs in non-cultivated fields, along roadsides, in waste places, and around settlements. Introduced from Europe.
Brassica juncea (L.) Czern., Indian mustard, moutarde d’Inde
Annual, spreading by seeds; stems to 4 feet (12 dm.) high;
flowers yellow; throughout our area, but most common in the
mid-west; cultivated fields, roadsides, and waste places;
introduced from Europe and Asia.
Brassica rapa L. [ =Brassica campestris L.], bird rape, moutarde des oiseaux
Annual or winter annual, spreading by seeds; stems 8 inches to 3
feet (20 cm. to 9 dm.) high; flowers yellow; throughout our
area, but most common in the eastern and western maritime parts;
cultivated fields, waste places, and roadsides; introduced from
Europe and Asia.
Camelina microcarpa DC., small-seeded false flax, caméline à petite fruits
Annual or winter annual, spreading by seeds; autogamous; stems 1
to 3 feet (3 to 9 dm.) high; flowers pale yellow; throughout our
area, but much commoner in the mid-west; open prairie,
cultivated fields, roadsides, railway beds, and waste places;
introduced from Europe and Asia. Originally spread as a
contaminant in flax and grain seed. Capsella bursa-pastoris (L.) Medik., shepherd's purse, bourse-à-pasteur
Annual or winter annual, propagating by seeds; autogamous; stems
very short to 3 feet (9 dm.) high; flowers white; present in all
settled areas within our range; cultivated fields, pastures,
meadows, roadsides, railway beds, and waste places; introduced
from Europe. Recorded in New England as early as 1672.
Cardaria chalepensis (L.) Hand.-Mazz., lens-podded hoary cress, cranson rampant
Strongly rhizomatous perennial; allogamous; stems 8 inches to 2
feet (20 cm. to 6 dm.) high; petals white; an aggressive weed in
the dryer areas of the mid-west and west, very rare in the east;
cultivated land, hayfields, roadsides, and waste land,
especially where irrigated. Both this weed and globe-podded
hoary cress (Cardaria pubescens) were introduced into North
America in alfalfa imported from Turkestan in 1911 and 1912.
They are, even now, often found growing together at the same
location. However, lens-podded hoary cress is by far the most
aggressive weed.
Conringia orientalis (L.) Dumort., hare's-ear mustard, vélar d’Orient
Annual or winter annual, spreading by seeds; autogamous;stems 6
inches to 2 feet (15 cm. to 6 dm.) high; the entire plant is
slightly succulent; flowers creamy white; throughout our range,
but most common in the mid-west; grain fields, gardens, waste
places, railroad beds , and roadsides; introduced from Europe.
Descurainia sophia (L.) Webb ex Prantl, flixweed, sagesse-des-chirurgiens
Annual or winter annual, spreading by seeds; autogamous; stems
up to 3 feet (9 dm.) high; flowers yellow; found throughout our
area, but most common in the mid-west; disturbed grasslands,
hayfields, roadsides, and waste places; introduced from Europe.
Draba nemorosa L., wood whitlow-grass, drave des bois
A small autogamous annual or winter annual with pale yellow flowers; native to the western half of our area and introduced in the eastern half. It has colonized a wide range of disturbed habitats both within and outside of its native range.
Erucastrum gallicum (Willd.) O.E.Schulz, dog mustard, moutarde des chiens
Annual or winter annual, spreading by seeds; autogamous; stems 6
inches to 2 feet (15 cm. to 6 dm.) high; flowers pale yellow;
throughout our area, but reaches its greatest abundance in the
mid-west; cultivated fields, roadsides, railway beds, and waste
places; introduced from Europe and Asia. It was first seen in
1903, in the United States.
Erysimum cheiranthoides L., wormseed mustard, vélar fausse-giroflée
Annual or winter annual, reproducing by seeds; autogamous; stems
3 inches to 4 feet (8 cm. to 12 dm.) high; present throughout
our area; in a wide range of disturbed habitats, but is usually
sparse at any single location; introduced from Europe and Asia.
It was first recorded, in Virginia, in 1814.
Erysimumhieraciifolium L., tall wormseed mustard, vélar à feuilles d’épervière
Biennial to perennial, reproducing by seeds; apomictic; stems 6
inches to 6 feet (15 cm. to 18 dm.) high; flowers yellow;
eastern part of our range; reaches its greatest abundance, and
is spreading rapidly in roadsides, gravel pits, pastures, and
hayfields in eastern Ontario, and northeastern New York. It was
first recorded at Ottawa, Ontario, in 1941; introduced from
Europe.
Hesperis matronalis L., dame’s-rocket, julienne des dames
Perennial, often many stemmed, 3 feet. (9 dm.) tall or higher. Flower color varies from white to purple. Introduced from Europe as an ornamental plant and now naturalized near old garden sites, in waste places, and along roadsides. It is locally a troublesome weed in Alaska, Canada, and the northern United States. It is sometimes confused with species of the genus Phlox. The flowers of dame’s-rocket have 4 petals and the stems have alternate leaves; Phlox always has 5-petalled flowers and stems with opposite leaves. Our dame’s-rocket has the chromosome number of 2n= 24.
Lepidium campestre (L.) R.Br. in W.T.Aiton, field pepper-grass, lépidie des champs
Annual or winter annual, spreading by seeds; autogamous; 6 to 18
inches (15 to 45 cm.) high; flowers white; throughout our area,
but most common in the southern parts of the eastern
non-maritime regions, and in southern British Columbia, western
Montana, Idaho, Washington, and Oregon; cultivated fields,
roadsides, waste places, and railroad beds; introduced from
Europe. Lepidium densiflorum Schrad., common pepper-grass, lépidie densiflore
Annual or winter annual, spreading by seeds; autogamous; stems 8
inches to 2 feet (20 cm. to 6 dm.) high; flowers white, but
inconspicuous; throughout our range, native to dry areas of
mid-west and west, and introduced elsewhere; prairie,
rangelands, cultivated fields, roadsides, and waste places.
Lepidium virginicum L., poor-man's pepper-grass, lépidie de Virginie
Annual, spreading by seeds; autogamous; stems a few inches to 2
feet (a few cm. to 6 dm.) high; flowers white; eastern North
America, southwestern British Columbia, and western Washington
and Oregon; mostly in roadsides, waste places, and around
settlements; native to North America, but probably seldom in its
native habitats.
Neslia paniculata (L.) Desv., ball mustard, neslie paniculée
Annual or winter annual, spreading by seeds; autogamous; plants
1 to 3 (3 to 9 dm.) high; flowers bright yellow; throughout our
area, but most common in cultivated fields of the mid-west;
cultivated fields, roadsides, railway embankments, waste places,
and near grain elevators; introduced from Europe. Its pods, that
do not open when ripe, are a frequent impurity in grain seed.
Raphanus raphanistrum L., wild radish, radis sauvage
Annual or winter annual, spreading by seeds; stems 1 to 3 feet
(3 to 9 dm.) tall; flowers usually yellow, but sometimes also
white or purple in the west, where it probably hybridizes with
the cultivated radish; abundant in cultivated fields, roadsides,
and waste places along the Atlantic seaboard, in southwestern
British Columbia, and in western Washington and Oregon;
introduced from Europe.
Rorippa sylvestris (L.) Besser, creeping yellow cress, rorippe sylvestre
Rhizomatous perennial, spreading mainly by root fragments;
flowers on the same plant are self-incompatible, and since, at
most locations all plants are genetically one plant that have
become established and spread by root fragments, creeping yellow
cress rarely produces seed pods and seeds in nature; flowering
stems 3 to 12 inches (8 to 30 cm.) high; throughout our area and
often locally weedy, especially in moist habitats; gardens,
ditches, disturbed stream banks, plant nurseries, and waste
places; introduced from Europe.
Sinapis arvensis L., wild mustard, moutarde des champs
Annual, reproducing by seeds; some autogamy, mostly allogamous;
stems 1 to 3 feet (3 to 9 dm.) high; flowers yellow; throughout
our area but most abundant in the grain fields and grasslands of
the mid-west; cultivated fields, row crops, waste places and
roadsides. Introduced from the Mediterranean region. Common in
the fields at Albany , New York, as early as 1748. Recent
reports that this plant was present in the northeastern United
States at 8000 years before the present time are unconvincing.
Poisoning and death of livestock has occurred when large
quantities of screenings were fed to cattle.
Sisymbrium altissimum L., tumble mustard, sisymbre élevé
Annual or winter annual, spreading by seeds; autogamous;
flowering stems 1 to 4 feet (3 to 12 dm.) high; pale yellow
flowers; throughout our area, but most abundant in grain fields
and grasslands of the mid-west; in roadsides, railway beds, and
waste places elsewhere; introduced from Europe and Asia. Often
breaking off at the base, acting as a tumbleweed for seed
dispersal. Sisymbrium loeselii L., tall hedge mustard, sisymbre de Loesel
Annual or winter annual, spreading by seeds; autogamous; plants
up to 4 feet (12 dm.) high; flowers bright yellow; throughout
most of our area, but most common in grain fields and other
cultivated fields of the mid-west; sporadic in roadsides and
waste places elsewhere; introduced from Europe.
Thlaspi arvense L., stinkweed, tabouret des champs
Annual or winter annual spreading by seeds; autogamous; plants
very short to 2 feet (6 dm.) high; flowers white; occurs
throughout our range; in cultivated fields, hayfields, gardens,
roadsides, railway beds, and waste places. Introduced from
Europe. A common weed around Detroit as early as 1818. Produces
an off-flavor in dairy products when grazed by cows.
Click here for information about all of the weedy mustards of Canada. All mustard photos labeled WHW are of illustrations prepared by W.H.Wright for Weeds of Canada by Clarence Frankton and Gerald A. Mulligan (1970), Agriculture Canada Publication 948, Ottawa, Ontario, 217 pages.
WHW- Upper left: Indian mustard, moutarde d’Inde. Upper right: bird rape, moutarde des oiseau. Lower left: black mustard, moutarde noire, Brassica nigra (L.) W.D.J.Koch. Lower right: white mustard, moutarde blanche, Sinapis alba L. In all drawings: A, pods; B, seed
bird rape, moutarde des oiseaux
bird rape, moutarde des oiseaux
bird rape, moutarde des oiseaux (cotyledon stage)
bird rape, moutarde des oiseaux
bird rape, moutarde des oiseaux (stereoscan photomicrograph of seed coat, from Mulligan & Bailey, Economic Botany 30:143-148, 1976)
small-seeded false flax, caméline à petite fruits (herbarium specimen)
WHW- small-seeded false flax, caméline à petite fruits: A, plant; B, pod; C, seeds. Large-seeded false flax, caméline cultivée, Camelina sativa ( L.) Crantz: D, seeds.