(55) 



2. Nasturtium. — Siliqua linear. Valves 

 without nerves. Ovules in each cell oo, 

 2-seriate. 



3. Cheiranthus. — Siliqua laterally com- 

 pressed. Septum broad. Valves 1- 

 nerved. Ovules in each cell 1-seriate. 

 Lateral sepals saccate. Petals unguicu- 

 late. 



4. Caulanthus. — Siliqua terete, valves 1- 

 nerved. Ovules in each cell 1-seriate 

 Lateral sepals saccate. Petals undulate. 



5. Streptanthus. — Siliqua laterally com- 

 pressed. Valves 1-nerved. Ovules in 

 each cell 1-seriate. All sepals equal. 

 Petals undulate. 



6. Barbarea. — Siliqua 4-angular. Valves 

 concave, 1-nerved. Ovules in each cell 

 1-seriate. 



7. Erysimum. — Siliqua 4-angular. Valves 

 carinate, 1-nerved. Ovules in each cell 

 1-seriate. 



8. Tropidocarpum. — Siliqua dorsally com- 

 pressed. Valves 1-nerved, carinate. 

 Septum very narrow. Ovules in each 

 cell 2-seriate. 



9. Arabis. — Siliqua laterally compressed. 

 Valves 1-nerved. Ovules in each cell 

 1-seriate. Petals not undulate. 



