CRUCIFERAE 



MUSTARD FAMILY 



WESTERN WALLFLOWER 



Erysimum asperum DC. 



Orange-yellow is an unusual flower color, not only in the 

 Mustard family but among flowers in general. The large bright 

 orange-yellow flowers of the Western Wallflower therefore have 

 undoubted value in attracting 

 certain insects that will ac- 

 complish pollination, and they 

 make this plant a very con- 

 spicuous inhabitant of open 

 places and woodland borders. 

 It is found only locally from 

 Illinois and Ohio to Newfound- 

 land but is more common 

 westward to Colorado and 

 New Mexico. 



The stem, 1-3 feet tall, is 

 slightly rough with short hairs 

 and is usually simple but may 

 branch near the top. The stem 

 leaves may be somewhat 

 toothed as shown, or they may 

 be entire. Lower leaves are 

 somewhat larger and they 

 taper into short petioles. 



The flowers have the usual 

 4 sepals, 4 petals, 6 stamens 

 and I pistil, and bloom from 

 April to July. The pods are 

 4-sided and contain 2 rows of 

 seeds. 



The Wormseed Mustard, Erysimum cheiranthoides L., blooms 

 in July and August along the banks of streams and in the open. It 

 is found locally in river bottoms throughout Illinois. The slender 

 and branching stem is roughish and the lanceolate leaves are barely 

 toothed. The small pods are upright on slender spreading pedicels, 

 and are blunt angled. The flowers are the usual Mustard family 

 yellow. Treacle Mustard or Tarrify are other names given it in 

 various parts of its range, from Newfoundland through New Jersey 

 to Missouri and the Pacific coast. 



129 



