436 TETRADYNAMIA. 



Class 15. Tetradynamia. Stamens 4 long 

 and 2 short. Orders 2, perfectly natural. 

 Flowers cruciform. 



1. Siliculosa. Fruit a roundish pod, or pouch. 

 In some genera it is entire, as Draba, 

 E?igL Bot. t. 586, and the Honesty or 

 Satin flower Lunaria : in others notched, 

 as Thlaspi, t. 1659, and Iberis, t. 52; 

 which last genus is unique in its natural 

 order in having unequal petals. Crambe, 

 t.9%&; Isatisy t.97', and Bunias, t.231; 

 certainly belong to this Order, though 

 placed by Linnaeus in the next. 



2. Siliquosa. Fruit a very long pod. Some 

 genera have a calyx clausus, its leaves 

 slightly cohering by their sides, as Rapha- 

 nus, t. 856 ; Ckeiranthus, t. 462 ; Hes- 

 peris, t. 731 ; Brassica, t. 637 > &c. 

 Others have a spreading or gaping calyx, 

 asCWrfamme, 1. 1000; Sisymbrium, t. 855 ; 

 and especially Sinapis, t. 969 and t. 1677- 



Cleome is a very irregular genus, allied 

 in habit, and even in the number of sta- 

 mens of several species, to the Bolyandria 

 Monogynia. Its fruit, moreover, is a cap- 

 sule of one cell, not the real two-celled 



