CRUCIPEEjE. 



59 



stalks, stiff and glabrous, 1 to 1^ inches 

 long, nearly cylindrical, but with a very 

 prominent midrib on each valve. 



Under hedges, in shady waste or cul- 

 tivated places, over the greater part of 

 Europe and western Asia, but not an 

 Arctic plant. Frequent in Britain gene- 

 rally, but decreasing much in northern 

 and western Scotland. Fl. spring. 



Fig. 71. 



XL EYSmUM. EKYSIMUM. 



Erect annuals or perennials, pale or hoary with closely appressed 

 hairs, rarely quite glabrous ; the leaves entire, or slightly toothed. 

 Flowers yellow, or rarely yellowish- white. Pod linear, nearly quad- 

 rangular from the very prominent midrib of the valves. Stigma broadly 

 capitate, or with short, spreading lobes. Seeds ovoid or oblong, the 

 seedstalk not flattened, the radicle incumbent on the back of one of the 

 cotyledons. 



A rather numerous genus in the northern hemisphere, differing from 

 Wallflower in the seeds, from Sisymbrium by the midrib of the valves 

 of the pod more prominent than in all the species of that genus except 

 the common S. 



Plant slightly hoary. Leaves tapering at the base .... 1. Common -E r . 

 Plant glabrous and glaucous. Leaves clasping the stem, and 



rounded at the base 2. Eastern E. 



1. Common Erysimum. Erysimum cheiranthoid.es, Linn. 



(Fig. 72.) 

 (Eng. Bot. t. 942. Treacle Mustard.) 

 A stiff, erect annual, 1 to 2 feet high, slightly hoary with closely ap- 

 pressed hairs. Leaves numerous, of a pale green, broadly lanceolate, 

 entire or slightly toothed, tapering into a short stalk at the base. 



f2 



