Brassicaceae

This is a large and difficult family; the separation between genera (and often species) is not always clear. It includes many common weeds as well as familiar ornamental and food plants.

The fruit is composed of 2 carpels, which typically separate at maturity from the base upwards, leaving a membranous partition or septum in a little frame attached to the pedicel. An elongate linear fruit is called a silique; a short stubby one, a silicle. In a very few species, the fruit is indehiscent, or breaks transversely. The distinctive flower, typically with 4 sepals, 4 petals, and 6 stamens (4 long and 2 short), together with the unique fruit type, make this an easily recognized family even if the species are sometimes troublesome to distinguish.

Most keys to Brassicaceae stress important characters of the ripe fruit, even of the embryo. If one has mature fruit, flowers with the color known, and an intact plant with cauline and (if any) basal leaves, identification is facilitated. Fortunately, most plants will still bear a few flowers while fruit is ripening on the lower part of the inflorescence. Even very young fruit at the base of the inflorescence will suggest the ultimate shape (silique or silicle); and with a little intuition one may also be able to predict the size to which partly developed fruits might grow. The keys here avoid characters of ripe fruit (and seeds) as much as possible. Often, characters of both flowers and fruit, as well as vegetative parts, are included, so that with some experimentation it should be possible to find where even an incomplete specimen belongs. In part because of easy shriveling of the claw (the narrowed basal part of a petal), dry petals may appear to be shorter than they really are. Intact, flat (well-pressed), unshriveled petals should be used to determine length. The style persists as an indehiscent beak on the fruits of some species. It is thus a part of the fruit and fruit measurements include the beak if any, unless only the body or valves are mentioned. The length of the beak is measured from the end of the valves and includes any stigma.

1. Petals pale to deep yellow.

2. Leaves (at least the middle or lower ones) ± deeply lobed (sinuses at least halfway to midrib), pinnatifid, or dissected.

3. Cauline leaves mostly deeply pinnatifid, appearing dissected (almost parsley-like), the ultimate segments mostly less than 2 mm broad; stem pubescence in our common species largely of forked, stellate, and/or glandular hairs.

4. Fruit a linear silique; all leaves ± dissected; stem pubescence largely of forked, stellate, and/or glandular hairs.

Descurainia

4. Fruit a round silicle; distal leaves simple, entire, strongly auriculate-clasping; stem glabrous.

Lepidium perfoliatum

3. Cauline leaves at most once-pinnatifid, at least the terminal segment more than 2 mm broad (except sometimes in Sisymbrium altissimum); stem pubescence absent or of simple hairs, not glandular (except in Bunias).

5. Pedicels (at least lower ones) subtended by pinnatifid bracts.

Erucastrum

5. Pedicels all bractless.

6. Cauline leaves strongly clasping the stem with well developed auricles.

7. Petals less than 3 mm long; fruit less than 5 times as long as broad.

Rorippa (in part)

7. Petals 4–14 (–16) mm long; fruit becoming over 10 times as long as broad.

8. Distal leaves mostly ± pinnatifid (with at least 1 pair of narrow lobes) or with angular teeth; fruit with beak not over 3.1 mm long.

Barbarea

8. Distal leaves entire to obscurely toothed or scalloped; fruit with beak 5–15 mm long.

Brassica (in part, couplet 2)

6. Cauline leaves sessile to petioled but not clasping.

9. Petals 10–20 mm long; style at least 1.5 mm long, soon elongating into a prominent beak on fruit.

10. Ovary and fruit on a distinct short stalk ca. 0.5–1 mm long (easily seen as a zone of different shade or texture above the receptacle just after flowering); fruits indehiscent, very strongly constricted (and ultimately breaking) between the ripe seeds.

Raphanus raphanistrum

10. Ovary and fruit sessile; fruits dehiscent at maturity, slightly if at all swollen around the seeds.

11. Petals ca. 15–20 mm long, pale yellow (drying translucent) with conspicuous purple veins; ripe fruit with body ca. 4–5 mm thick.

Eruca (in part)

11. Petals 10–16 mm long, bright yellow, veins various; ripe fruit less than 4 mm thick.

12. Distalmost leaves toothed; veins of petals not darker.

Sinapis (in part)

12. Distalmost leaves pinnatifid; veins of petals darker than rest of petal.

Coincya

9. Petals less than 10 mm long; style usually shorter than 1.5 mm or absent, elongating at most into a beak ca. 2 mm long (longer in Brassica).

13. Fruit (and maturing ovary) nearly spherical to broadly ovoid or short-oblong, less than 5 times as long as wide.

14. Fruit indehiscent, 1–4 (usually 2)-seeded, asymmetrically ovoid, the surface with irregular warts or ridges; principal leaves with terminal lobe much larger than lateral ones, 2–7 cm broad; stem with scattered sessile or short-stalked glands.

Bunias

14. Fruit readily dehiscent, many-seeded, nearly spherical to oblong or cylindrical (often slightly curved), smooth; principal leaves with terminal lobe less than 2.5 cm broad (very rarely to 3.5 cm); stem without glands.

Rorippa (in part)

13. Fruit (and maturing ovary) slender, ± linear, attaining a length at least 10 times as great as the width.

15. Petals less than 5.5 mm long; fruit in common species less than 2 cm long.

16. Plant usually in moist ground, the stem usually ± lax or prostrate, reproducing vegetatively (ripe seeds not formed); terminal lobe of most leaves scarcely if at all broader than lateral lobes.

Rorippa sylvestris

16. Plant usually in dry ground, the stem erect, reproducing by seed; terminal lobe of most leaves much broader than lateral lobes.

Sisymbrium (in part)

15. Petals (5–) 5.5–9.5 mm long; fruit often longer than 2 cm.

17. Beak of fruit 7–14 mm long at maturity, the style soon exceeding 4 mm after flowering.

18. Uppermost leaves entire or nearly so, narrow (including petiole if any, ca. 5–10 times as long as wide); fruit without parallel nerves besides margins and mid-nerves (additional nerves, if any, ± looped or anastomosing), glabrous; petals 7–10 mm long.

Brassica (in part)

18. Uppermost leaves (e.g., at base of main branches of inflorescence) coarsely toothed, ca. 2–4 times as long as broad; valves of fruit each with 2 or 4 distinct parallel nerves besides the midnerves and margins or fruits densely hispid; petals (8–) 10–15 mm long.

Sinapis (in part)

17. Beak of fruit less than 4 mm long, or none.

19. Buds overtopping open flowers; pedicels and fruit becoming closely appressed to axis of inflorescence.

Brassica nigra

19. Buds mostly overtopped by open flowers; pedicels and fruit spreading.

20. Ovules and seeds in 2 rows in each locule (easily seen on pressed dried immature fruit or as 2 rows of seeds or depressions in septum of mature fruit).

Diplotaxis (in part)

20. Ovules and seeds in 1 row in each locule.

Sisymbrium (in part)

2. Leaves all unlobed, entire or toothed.

21. Cauline leaves sagittate- or auriculate-clasping at the base.

22. Body of fruit ± spherical or obovoid; distal leaves (like the proximal) with forked or stellate and/or simple hairs (at least a few on margins).

23. Axis of inflorescence glabrous; petals 3.5–4.5 (–5) mm long; fruit dehiscent, several-seeded, ca. (3–) 4–5 mm broad, the body weakly if at all reticulate.

Camelina

23. Axis of inflorescence at least sparsely pubescent; petals up to 2.5 mm long; fruit indehiscent, 1–2-seeded, less than 2.5 mm broad, the body strongly reticulate.

Neslia

22. Body of fruit elongate, linear (the shape evident as ovary matures); distal leaves (not always the proximal) glabrous.

24. Stem and leaves glabrous; petals ca. (7–) 8–12 mm long; leaves broadly rounded at apex.

Conringia (in part)

24. Stem and leaves pubescent at very base of plant; petals less than 7 mm long; leaves acute.

Turritis (in part)

21. Cauline leaves merely sessile, not clasping.

25. Plant glabrous or with simple hairs; fruit a linear silique ca. 1–4.5 cm long.

26. Petals (5–) 5.5–7.5 mm long; ovules and seeds in 2 rows in each locule (easily seen on pressed dried immature fruit or as 2 rows of seeds or depressions in septum of mature fruit).

Diplotaxis (in part)

26. Petals 7–15 mm long; ovules and seeds in 1 row in each locule.

27. Distalmost leaves entire or nearly so, narrow (including petiole if any, ca. 5–10 times as long as wide); fruit without parallel nerves besides margins and mid-nerves (additional nerves, if any, ± looped or anastomosing), glabrous; petals 7–10 mm long.

Brassica (in part, couplet 3)

27. Distalmost leaves (e.g., at base of main branches of inflorescence) coarsely toothed, ca. 2–4 times as long as broad; valves of fruit each with 2 or 4 distinct parallel nerves besides the midnerves and margins or fruits hispid; petals (8–) 10–15 mm long.

Sinapis (in part)

25. Plant pubescent with stellate or forked hairs; fruit various.

28. Fruit 4-sided or ± terete, at least 15 mm long; petals 3.5–10 mm long.

Erysimum

28. Fruit strongly flattened (parallel to the septum), less than 10 mm long; petals less than 4 (–6) mm long.

29. Fruit elongate (ca. 3–5 times as long as broad), ca. 5–9 mm long; ovules and seeds numerous in each locule; leaves slightly toothed, ovate to elliptic.

Draba (in part)

29. Fruit round or nearly so, ca. 4 (–5) mm or less long; ovules and seeds 1–2 in each locule; leaves entire, linear to oblanceolate.

30. Basal leaves smaller than cauline leaves promptly withering and often absent; silicles stellate-pubescent.

Alyssum (in part)

30. Basal leaves much larger than the cauline leaves, persistent; silicles glabrous.

Aurinia

1. Petals white to purple, or none.

31. Principal cauline leaves deeply lobed (e.g., lyrate or pinnatifid) or compound (uppermost leaves or bracts, at the inflorescence, or above water in aquatics, may be simple).

32. Leaves palmately compound or deeply palmately divided, the cauline only 2 or 3 (–4).

Cardamine (in part)

32. Leaves pinnately lobed or divided, the cauline often more than 3.

33. Plant truly aquatic, the submersed leaves dissected in a bipinnate pattern into filiform segments (midvein present, the lateral segments again dissected), frequently detaching readily from the stem.

Rorippa aquatica

33. Plant terrestrial or aquatic but even if in water the leaves with definite flat lobes (not bipinnately dissected) and not falling from the stem.

34. Petals ca. 15–20 mm long and undersides of stem leaves glabrous or with a few weak hairs on the midvein.

Eruca (in part)

34. Petals less than 15 mm long or if longer, then leaf blades or leaflets with short stiff conical hairs ca. 0.3–0.5 mm long on undersides.

35. Leaf blades or leaflets with short stiff hairs ca. 0.3–0.5 mm long on margins or undersides; petals at least 10 mm long; mature fruit elongate, ca. 3–12 mm thick, indehiscent.

Raphanus (in part)

35. Leaf blades or leaflets glabrous or with finer smaller hairs, or if blades ciliate, the petals much less than 10 mm long; mature fruit narrower or round, dehiscent.

36. Fruits less than twice as long as broad, with 1–2 seeds in each locule; plant an erect weed of usually dry places.

37. Petals less than 4 mm long; fruit strongly flattened; habitat dry.

38. Plants with well-developed cauline leaves; seeds 1 per locule.

Lepidium (in part)

38. Plants scapose; leaves in a basal rosette, cauline leaves absent or reduced; seeds 2 per locule.

Teesdalia

37. Petals at least 5 mm long; fruit ± spherical; habitat dry to wet.

Armoracia (in part)

36. Fruits soon becoming more than twice as long as broad, many-seeded; plant often ± lax, usually in wet ground or water.

39. Petals at least 7 mm long.

Cardamine pratensis

39. Petals less than 6 mm long.

40. Fruits straight, ± erect, on ascending pedicels; seeds smooth; plants often with a basal rosette (at least when young and if not submersed), the stems not forming extensive creeping mats; petals 0–3.5 (–4.5) mm long.

Cardamine (in part)

40. Fruits often ± curved, spreading (the pedicels soon divergent after flowering); seeds reticulate; plants without basal rosette, the stems elongated and ± prostrate or ascending, forming mats; petals (2.5–) 3.5–5.7 mm long.

Nasturtium

31. Principal cauline leaves (if any) simple, unlobed (except for clasping base in some species), entire or toothed.

41. Stems and/or leaves (especially beneath and along margins) pubescent with many or all of the hairs stellate or forked (check especially lower leaves).

42. Cauline leaves sagittate- or auriculate-clasping.

43. Fruit strongly flattened at right angles to the septum, ± triangular to obcordate, less than twice as long as broad; petals less than 3 mm long.

Capsella

43. Fruit plump or flattened parallel to the septum, linear (straight or curved), becoming at least 10 times as long as broad; petals usually at least 4 mm long (less than 3 mm in Boechera dentata).

44. Fruiting pedicels strongly ascending to appressed; fruits straight, erect and closely appressed to the stem.

45. Stem and leaves entirely glabrous or with a very few scattered simple and/or appressed medifixed hairs at the very base of the plant (especially on leaf margins and petioles); sepals ca. half as long as the petals; mature fruit 1.4–2.5 (–3.3) mm broad, with seeds in 2 rows in each locule.

Boechera stricta

45. Stem and leaves pubescent, at least at the base, with spreading simple or stellate hairs (sparse appressed medifixed hairs rarely in Arabis pycnocarpa); sepals ca. 65–75% as long as the petals; mature fruit less than 1.3 (very rarely 1.5) mm broad, with seeds crowded into 1 row in each locule.

46. Fruit rather strongly flattened; style-beak clearly narrower than mature fruit; stem pubescent with simple and/or forked (or stellate) hairs on at least the lower half or third, and leaves on the same portion ± pubescent (often stellate).

Arabis pycnocarpa

46. Fruit ± terete or 4-angled, slightly if at all flattened at maturity; style-beak nearly or quite as wide as the fruit; stem pubescence only on the lowermost 1–3 full-grown internodes, and only the lowermost leaves pubescent.

Turritis (in part)

44. Fruiting pedicels ± spreading, divaricate, or reflexed; fruits straight or somewhat curved and clearly spreading from the axis or even pendent.

47. Petals 9–14 mm long; plant a procumbent tufted, fibrous rooted escape from cultivation with numerous vegetative rosettes.

Arabis caucasica

47. Petals 2–9 mm long; plant a tall native with few or no vegetative rosettes, tap-rooted.

Boechera (in part)

42. Cauline leaves (if any) petioled or sessile but not clasping the stem.

48. Body of fruit (and maturing ovary) slender, ± linear, attaining a length at least 10 times its width.

49. Petals ca. (13–) 15–20 (–25) mm long, purple, lavender, pink, or white.

Hesperis

49. Petals less than 10 mm long, white or slightly tinged with color.

50. Fruit curved, pendent on reflexed pedicels; leaves (at least lower ones) (4–) 6–12 (–16) cm long; basal rosette absent at flowering time.

Boechera canadensis (in part)

50. Fruit straight, on ascending pedicels; leaves less than 3.5 (–4.5) cm long, basal rosette of usually toothed (except in Arabis procurrens) or lyrate-lobed blades often present at flowering time.

51. Plant with well-developed stolons; leaves all entire, at least the basal ones with appressed medifixed hairs on margins and midrib beneath; petals ca. 8–9 (–10) mm long.

Arabis procurrens

51. Plant without stolons; basal leaves ± toothed or lobed (sometimes absent in fruiting plants), pubescent or glabrous but without medifixed hairs; petals ca. 2–8 (–9) mm long.

52. Axis of inflorescence and pedicels glabrous, often ± glaucous.

Arabidopsis (in part)

52. Axis of inflorescence and pedicels finely pubescent.

Braya

48. Body of fruit (and maturing ovary) never linear, but short-oblong, ovate to narrowly elliptic, or round, less than 6 (–8) times as long as wide.

53. Petals deeply bilobed.

54. Stems leafy, without a basal rosette; petals 4–7 mm long; fruit pubescent, with ± convex sides and persistent slender style; plant perennial (usually), blooming in early to late summer.

Berteroa

54. Stems leafless, all leaves in a basal rosette; petals 1.5–3 mm long; fruit glabrous, with flat sides and no evident style; plant annual, blooming in early spring (April).

Draba verna

53. Petals entire or slightly notched at apex (or absent).

55. Pubescence mostly (or entirely) of appressed medifixed hairs (evident on leaves, stems, and inflorescences); seed 1 in each locule.

Lobularia

55. Pubescence mostly of branched (or stellate) or simple hairs, without appressed medifixed ones; seeds 2–many in each locule.

56. Fruit round or nearly so, ca. 4 mm or less long; ovules and seeds 2 in each locule; leaves all entire, cauline (or on short basal shoots), without basal rosette.

Alyssum (in part)

56. Fruit elongate, elliptic or narrowly oblong to ovate (2.5–8 times as long as wide), at least 5 mm long; ovules and seeds numerous in each locule; leaves mostly in a basal rosette or toothed (or both).

Draba (in part)

41. Stems and leaves glabrous or with only simple hairs (occasionally a few forked hairs may be intermixed).

57. Cauline leaves sagittate- or auriculate-clasping.

58. Fruit (and maturing ovary) linear, becoming at least (1.5–) 3 cm long; petals ca. 3–12 mm long.

59. Stem and leaves pubescent (at least at base), some leaves basal, leaves toothed, and/or leaves acute.

Boechera (in part)

59. Stem and leaves completely glabrous; leaves all cauline, entire and broadly rounded at the apex.

Conringia (in part)

58. Fruit (and maturing ovary) round to obovate (flattened to nearly spherical), less than twice as long as broad and not over 1.5 (–2) cm long; petals not over 4 mm long (or absent).

60. Plant slightly to densely pubescent; ovules and seeds 1 per locule; fruit less than 5.5 mm broad at maturity.

Lepidium (in part)

60. Plant glabrous; ovules and seeds 3–7 in each locule; fruit ca. 3.5–12 (–20) mm broad at maturity.

61. Fruit 7–12 (–20) mm broad at maturity, deeply notched with the notch deeper than wide.

Thlaspi

61. Fruit 3.5–6 mm broad at maturity, shallowly notched with the notch wider than deep.

Microthlaspi

57. Cauline leaves (if any) sessile or petioled, but not clasping the stem.

62. Petals 15–25 mm long, usually purple (rarely white); fruit very flat, at least 15 mm broad; leaves opposite, at least at middle and lower nodes.

Lunaria

62. Petals up to 14 mm long (to 16 mm in 2 species), white to pink (or absent); fruit even if flat less than 10 mm broad; leaves all alternate or basal.

63. Plant a small aquatic with all leaves basal and awl-shaped, usually flowering and fruiting under water.

Subularia

63. Plant with leafy stem, of moist or dry ground, not flowering under water.

64. Middle cauline leaves with toothed, triangular-ovate blades little if at all longer than broad, on slender petioles; bruised plant with odor of onion or garlic.

Alliaria

64. Middle cauline leaves with blades toothed or entire, distinctly longer than broad, sessile or tapered into petiole; plant without onion-garlic odor.

65. Leaves and branches with stalked glands.

Chorispora

65. Leaves and branches glabrous or variously pubescent but lacking stalked glands.

66. Leaves succulent, the margin ± irregularly sinuate-toothed; plant an annual of sandy shores of the Great Lakes, without basal leaves; petals ± pink; fruit not longitudinally dehiscent, but breaking transversely between the two (usually 0–1-seeded) segments, the terminal segment larger, usually tapering into a prominent beak.

Cakile

66. Leaves not succulent, the margin various (usually entire or regularly, even if remotely, toothed); plant of various habitats, most species with basal leaves (if somewhat succulent and on sandy shores, a small basal rosette of lyrate leaves usually present); fruit longitudinally dehiscent, with or without a beak.

67. Fruit (and maturing ovary) linear, becoming at least 10 times as long as broad.

68. Petals 8–14 (–16) mm long; basal leaves distinctly with a rounded blade and long slender petiole, arising from a tuberous root; pubescence (if any) of strictly simple hairs [check lower part of stem carefully].

Cardamine (in part, couplet 5)

68. Petals ca. 4–8 (–9) mm long; basal leaves (if any) not distinctly petioled, arising from a slender root; pubescence (if any) usually including a few stellate hairs [check basal leaves carefully].

69. Fruit straight, mostly (0.7–) 2–4 cm long, less than 1.3 mm broad, on ascending pedicels; leaves less than 3.5 (–4.5) cm long, including those in a basal rosette of usually toothed or lyrate-lobed blades normally present at flowering time; stem often branched at base.

Arabidopsis lyrata

69. Fruit curved, 4.5–7 (–8) cm long, (2–) 2.4–3.2 mm broad, pendent on reflexed pedicels; leaves (at least lower ones) (4–) 6–12 (–16) cm long, with no basal rosette evident at flowering time; stem simple.

Boechera canadensis (in part)

67. Fruit (and maturing ovary) round or spherical, or nearly so, less than twice as long as broad.

70. Largest cauline and basal leaves usually 3.5–30 cm broad, with ± rounded or obtuse teeth; basal leaves long-petioled; fruit ± ellipsoid-obovoid (not flattened), not notched at the apex, the several ovules not ripening into seeds.

Armoracia (in part)

70. Largest leaves less than 2.5 (–3.5) cm broad, entire or sharply toothed; basal long-petioled leaves none; fruit round or nearly so, strongly flattened, notched at apex, with 1 seed in each locule.

71. Petals distinctly unequal (2 large and 2 small), the larger ca. 5–9 mm long; style at least 1 mm long.

Iberis

71. Petals equal (if present), 0–2.2 (–3) mm long; style 0.5–1 mm long (to 1.5 mm if fruits not notched at apex).

Lepidium (in part)

All species found in Brassicaceae

Alliaria petiolataGARLIC MUSTARD 
Alyssum alyssoidesPALE ALYSSUM 
Alyssum muraleYELLOWTUFT 
Arabidopsis lyrataSAND CRESS 
Arabidopsis thalianaMOUSE-EAR CRESS 
Arabis caucasicaWALL ROCK CRESS 
Arabis procurrensHUNGARIAN ROCK CRESS 
Arabis pycnocarpaHAIRY ROCK CRESS 
Armoracia rusticanaHORSERADISH 
Aurinia saxatilisGOLDENTUFT 
Barbarea orthocerasNORTHERN WINTER CRESS 
Barbarea strictaYELLOW ROCKET 
Barbarea vernaEARLY WINTER CRESS 
Barbarea vulgarisYELLOW ROCKET 
Berteroa incanaHOARY ALYSSUM 
Boechera canadensisSICKLE-POD 
Boechera dentataROCK CRESS 
Boechera grahamiiROCK CRESS 
Boechera laevigataSMOOTH BANK CRESS 
Boechera missouriensisMISSOURI ROCK CRESS 
Boechera retrofractaROCK CRESS 
Boechera strictaDRUMMOND ROCK CRESS 
Brassica junceaINDIAN MUSTARD, CHINESE MUSTARD, BROWN MUSTARD 
Brassica napusRAPE, RUTABAGA 
Brassica nigraBLACK MUSTARD 
Brassica rapaFIELD MUSTARD, TURNIP 
Braya humilisLOW NORTHERN ROCK CRESS 
Bunias orientalisTURKISH ROCKET 
Cakile edentulaSEA-ROCKET 
Camelina microcarpaSMALL-FRUITED FALSE FLAX 
Camelina sativaFALSE FLAX 
Capsella bursa-pastorisSHEPHERD'S-PURSE 
Cardamine bulbosaSPRING CRESS 
Cardamine concatenataCUT-LEAVED TOOTHWORT 
Cardamine diphyllaTWO-LEAVED TOOTHWORT 
Cardamine douglassiiPINK SPRING CRESS 
Cardamine flexuosaBITTER CRESS 
Cardamine hirsutaHOARY BITTER CRESS 
Cardamine impatiensBITTER CRESS 
Cardamine maximaLARGE TOOTHWORT 
Cardamine parvifloraDRYLAND BITTER CRESS 
Cardamine pensylvanicaPENNSYLVANIA BITTER CRESS 
Cardamine pratensisCUCKOO-FLOWER 
Chorispora tenellaPURPLE ROCKET 
Coincya monensisWALLFLOWER CABBAGE 
Conringia orientalisHARE'S-EAR MUSTARD 
Descurainia pinnataTANSY MUSTARD 
Descurainia sophiaFLIXWEED 
Diplotaxis muralisWALL ROCKET 
Diplotaxis tenuifoliaSAND ROCKET 
Draba arabisansROCK WHITLOW-GRASS 
Draba canaASHY WHITLOW-GRASS 
Draba glabellaSMOOTH WHITLOW-GRASS 
Draba incanaTWISTED WHITLOW-GRASS 
Draba nemorosaWHITLOW-GRASS 
Draba reptansCOMMON WHITLOW-GRASS 
Draba vernaWHITLOW-GRASS 
Eruca vesicariaROCKET-SALAD, GARDEN ROCKET, ARUGULA 
Erucastrum gallicumDOG MUSTARD 
Erysimum capitatumWESTERN WALLFLOWER 
Erysimum cheiranthoidesWORMSEED MUSTARD 
Erysimum hieraciifoliumTALL WORMSEED MUSTARD 
Erysimum inconspicuumSMALL WORMSEED MUSTARD 
Erysimum repandumTREACLE MUSTARD 
Hesperis matronalisDAME'S ROCKET 
Iberis amaraROCKET CANDYTUFT 
Iberis sempervirensEVERGREEN CANDYTUFT 
Iberis umbellataGLOBE CANDYTUFT 
Lepidium appelianumWHITE-TOP 
Lepidium campestreFIELD CRESS 
Lepidium densiflorumSMALL PEPPERGRASS 
Lepidium drabaHOARY CRESS 
Lepidium montanumPEPPERGRASS 
Lepidium perfoliatumCLASPING CRESS 
Lepidium ruderaleFETID PEPPERGRASS 
Lepidium sativumGARDEN CRESS 
Lepidium virginicumCOMMON PEPPERGRASS 
Lobularia maritimaSWEET ALYSSUM 
Lunaria annuaMONEY-PLANT, HONESTY 
Microthlaspi perfoliatumCLASPLEAF PENNYCRESS 
Nasturtium microphyllumWATERCRESS 
Nasturtium officinaleWATERCRESS 
Neslia paniculataBALL MUSTARD 
Raphanus raphanistrumWILD RADISH 
Raphanus sativusRADISH 
Rorippa aquaticaLAKE CRESS 
Rorippa curvipesYELLOW CRESS 
Rorippa palustrisYELLOW CRESS 
Rorippa sylvestrisCREEPING YELLOW CRESS 
Sinapis albaWHITE MUSTARD 
Sinapis arvensisCHARLOCK, WILD MUSTARD 
Sisymbrium altissimumTUMBLE MUSTARD 
Sisymbrium irioLONDON ROCKET 
Sisymbrium loeseliiTALL HEDGE MUSTARD 
Sisymbrium officinaleHEDGE MUSTARD 
Subularia aquaticaAWL-WORT 
Teesdalia nudicaulisSHEPHERD'S CRESS 
Thlaspi arvensePENNY CRESS 
Turritis glabraTOWER MUSTARD 

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. April 26, 2017. http://michiganflora.net/family.aspx?id=BRASSICACEAE.