GENERA OF CLASS XV. TETRADYNAMIA. 



91 



top, beyond the valves, the prominent part thereof having be- 

 fore served as a style. 



Seeds— Roundish, inclining downwards, alternately plunged 

 lengthwise into the dissepiment. The receptacle linear, surround- 

 ing the dissepiment, and immersed in the sutures of the pericar- 

 pium. The orders are two, containing thirty-four genera, viz. 



Order L Siliculosa, comprehending those plants whose peri- 

 carpium is a silicula*. This order contains nineteen genera, sub- 

 divided into, 1. Silicle entire; that is, not emarginate at the top, 

 which contains nine genera, viz. Myagrum (gold of pleasure) ... 

 Vella (cress-rocket)... Sub ulari a (aivl-ivort) ...Draba (whitlow 



graSS ) ...LuNARlAfAoWf5^ > )...CAKlLE,..PuGIONIUM...BuNIAS ( Sea 



rocket)... and Crambe (colewort, or sea-kale). 2. Silicle emargi- 

 nate at the end, which contains ten genera. ..Iberis ( candy-tuft )... 

 Alyssum ( madzvort)... Clypeola ( treacle mustard ) ... Peltaria 

 ...Cochliaria ( scurvy -gr ass)... Lepidium (pepper -ivori)... Thlaspi 

 {rnithr\date mustard ) ... Is at is (ivoad)... BuscuTELLA...and Anas- 

 tatic a {rose of Jericho). 



Order 2. Siliquosa, comprehends those plants whose pericar- 

 pium is a siliquaf. This order contains fifteen genera, falling un- 

 der two divisions, 1 . Calyx closed, with the leaves converging longi- 

 tudinally, which contains ten genera, viz. Dentaria (tooth-ivort, 

 or coral-wort)... Erysimum (hedge mustard) ...Cheiranthus (wall- 

 flower, and stock gilliflower)... Hesperis (rocket)... Arab is (wall- 

 cress, and rock-cress)... Turritis (tower mustard)... Bhassica (cab- 

 bage, rape, or cole-seed, turnip)... Ratuanvs (radish)... Ricoti a... 

 and Cordylocarpus. 2. Calyx gaping, with the leaves distant 

 above, contains five genera, Cleome... Card amine (ladies 7 smock) 

 ...Sinapis (mustard)... Sisymbrium (water-cress, water-rocket)... and 

 Heliophila. 



* See the account of this order in Chap. III. f See Chap. III. 



