266 CLASS XV. ORDER I. 



291. Raphanus. Silique cylindrical, swelling at 

 the seeds, somewhat jointed. 



292. Cardamine. Siliqne bursting elastically, the 

 valves revolute, and equal to the partition. 



293. Sisymbrium. Silique cyUndrical, opening with 

 nearly straight valves ; valves equalling the partition. 



294. Erysimum. Calyx closed; stigma capitate; 

 silique columnar, square. 



295. SiNAPis. Calyx spreading; silique cylindri- 

 cal, with the partition longer than the valves. 



296. Dentaria. Silique opening elastically, the 

 valves revolute ; stigma emarginate ; calyx connivent. 



297. Cleome. Petals all ascending; glands three, 

 one at each sinus of the calyx except the lowest ; germ 

 stipitate ; silique one celled, two valved. 



TETRADYNAMIA. 



SILICULOSA. 



284. DRABA. 

 Draba verna. L, Mliiilow Grass. 



Scape naked; leaves oblong, acute, subserrate, 

 hairy; petals bifid ; stigma sessile. 



A small, very early, white flowering plant. Leaves all radical. 

 Scape two or three inches high with a raceme of small flowers. 

 Calyx spreading ; petals half cleft. Pod oval, flat. — Among the 

 grass in fields, &c. in the southern parts of the state. Not seen 

 near Boston. — April, May. 



285. LEPIDIUM. 

 Lepidium Virginicum. L. Wild Cress or Pcppergrass. 

 Radical leaves pinnatifid ; stem leaves linear-lanceo- 

 late, serrate; flowers with four petals and two stamens; 

 silicic lenticular. Mich. ab7\ 



