1. Petals ca. 18–24 mm long, (4–) 6–9 mm broad.

E. capitatum

1. Petals much smaller (less than 11 mm long and 4 mm broad).

2. Sepals 2.2–3.2 mm long; petals 3.5–5 (–5.5) mm long; fruit 1.5–2.5 cm long, ca. 2–3 times as long as the distinctly more slender pedicels; hairs on upper surface of leaves mostly 3- and 4-pronged.

E. cheiranthoides

2. Sepals (4–) 4.5–6.5 (–7.5) mm long; petals (6–) 7–9 (–10) mm long; fruit 2.5–8 cm long, ca. (5–) 6–20 or more times as long as the thick pedicels (nearly as thick as the fruit); hairs on upper surface of leaves various.

3. Fruit ca. 5–8 cm long, widely spreading; leaves remotely denticulate or shallowly sinuate, without 4-pronged hairs (all 2- and 3-pronged); plant annual, usually many-branched.

E. repandum

3. Fruit 2.5–5 cm long, strongly ascending or erect; leaves entire and without 4-pronged hairs or toothed and with 4-pronged hairs above; plant biennial or perennial, usually stiffly erect and unbranched.

4. Cauline leaves remotely toothed or denticulate, elliptic-lanceolate, often more than 5 mm broad, with both 3- and 4-pronged hairs above.

E. hieraciifolium

4. Cauline leaves entire, essentially linear, up to 5 mm broad, without 4-pronged hairs (all 2- and 3-pronged).

E. inconspicuum

All species found in Erysimum

Erysimum capitatumWESTERN WALLFLOWER 
Erysimum cheiranthoidesWORMSEED MUSTARD 
Erysimum hieraciifoliumTALL WORMSEED MUSTARD 
Erysimum inconspicuumSMALL WORMSEED MUSTARD 
Erysimum repandumTREACLE MUSTARD 


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. March 28, 2017.