Class XV. TETRADYNAMIA. 

 Stamens 6, 2 opposite ones sliortest. 



Order I. SILICULOSA. Fruit a short 

 roimdish pod, or pouch. 



* Cotyledons accumbent. 



318. DRABA. Pouch eniwe, laterally compressed; valves 



nearly flat. Seeds numerous. 



316. VELLA. Pouch entire, with a prominent, dilated, 



flat style, twice as long as the concave valves. 



330. CRAMBE. Pouch globose, stalked, coriaceous, of 

 1 cell, without valves, deciduous. Seed solitary. 



329. CAKILE. Pouch angular, of 2 joints, each of 1 

 cell, without valves; the uppermost deciduous. Seeds 

 solitary. 



322. HUTCHINSIA. Po?^cA nearly entire ; valves keel- 



ed, not bordered. Seeds 2, at least, in each cell. 

 Pilaments simple. 



319. ALYSSUM. Pouch nearly entire, bordered, late- 



rally compressed ; valves concave. Seeds 1 or 2 in 

 each cell. Filam. often toothed. 



325. COCHLEARIA. Pouch nearly entire, turgid, rug- 

 ged, of 2 valves. Seeds numerous. 



324. THLASPI. Pouch cloven, inversely heart-shaped ; 

 valves with a bordered keel. Seeds numerous. 



327. IBERIS. Pouch cloven, inversely heart-shaped. 

 Seeds solitary. 2 outer petals largest. 



323. TEESDALIA. Pouch cloven, inversely heart-shaped; 



valves keeled. Seeds 2 in each cell. Filam. each 

 bearing a scale at the base. 



** Cotyledons incimihent. 



317. SUBULARIA. Pouch entire, transversely com- 



