CKUCIFERAE 99 



1. I. pinnatifidus (Michx.) Steud. PURPLE KOCKET. l-3 high, 

 glabrous: leaves oblong in outline, dentate: pods 12"-18" long. In 

 rich woods throughout, but not common. May-July. 



8. RORIPA Scop. 



Flowers white or yellow. Pods from subglobose to oblong-linear. 

 Seeds numerous, marginless. Cotyledons acoumbent. The first four 

 species are known as YELLOW WATER CRESS. 



Flowers yellow. 



Perennial. 1. E. sinuata. 



Annuals. 



Seeds pitted. 2. R. sessiliflora. 



Seeds minutely tuberculate. 



Pedicels 1" long. 3. B. obtusa. 



Pedicels 2 // -4 // long. 4. R. palustris. 



Flowers white. 



Creeping and spreading. 5. R. Nasturtium. 



Erect. 6 B. Armoracia. 



1. R. sinuata (Nutt.) A. S. Hitchcock. Branches spreading and as- 

 cending, glabrous : leaves oblong, pinnately cleft : flowers 3 // -4 // broad : 

 pods 4 // -6 // long. Quite common in sandy soil along the Missouri 

 River. April-June. 



2. R. sessiliflora (Nutt.) A. S. Hitchcock. Erect, 6 / -12 / high: 

 leaves oblong, crenate and lobed : flowers 1" broad, nearly sessile : pods 

 oblong, thick Common with the next. April-November. 



3. R. obtusa (Nutt.) Britton. Much branched and spreading: leaves 

 pinnatifid : flowers V broad : pods oblong, l // -5 // long. Common on 

 sand-bars along the Missouri River. April-November. 



4. R. palustris (L.) Bessey. 6'-2 high, erect, glabrous: leaves 

 oblong, pinnatifid : flowers l // -2 // broad : pods about equalling the pedi- 

 cels. Common in wet places throughout. April-November. 



5. R. Nasturtium (L.) Rusby. WATER CRESS. Glabrous : leaves 

 divided into 3-9 oblong to orbicular segments : pedicels about W // long, 

 widely spreading and as long as the pods. In springs around Kansas 

 City. Common locally- May-August. 



6. R. Armoracia (L.) A. 8. Hitchcock. HORSE RADISH. 2-4 high, 

 from large rootstocks : leaves oblong, crenate to pinnatifid : pedicels 

 ascending: flowers large. Occasionally escaped along roads. May-July. 



9. CARDAMINE L. BITTER CRESS. 



Pods long, linear, with nerveless valves and seeds in a single row in 

 each cell. Cotyledons accumbent. 



Plants not from a tuberous base. 



Terminal leaf segment obovate to orbicular. 



Stems 8 / or more high, stout. 1. C. Pennsylvanica. 



Stems 2 / -5 / high, delicate. 2. C. parviflora. 



Terminal leaf segment linear to linear-oblong. 3. C. arenicola. 



Plants from a tuberous base. 4. C. bulbosa. 



