PARIETALE8. 



553 



0. pungens, of South America, are fine flowi-ring plants cultivated in 

 gardens. 



Order Cruciferee. The Cr ucifer Family. Herbs and a few low shrubs 

 with actinomorphic flowers, tetradynamous stamens, and seeds without 

 endosperm (Figs. 528-41). This large order includes 172 genera and 

 about 1200 species, which are distributed throughout the temperate re- 

 gions of the world, but are most abundant in Southern Europe and 

 Asia Minor. The prevailing principle in the order is pungent and stim- 

 ulant. 



The order is divided by Bentham and Hooker into ten tribes, distin- 

 guished by the shape of the fruit and the disposition of the cotyledons 

 in the seed, whether incumbent or accumbent (Figs. 536 to 541). 



The order furnishes a few food plants of some importance. 



Bra sica oleracea, a wild plant of the Atlantic coast of Europe, is 



FIGS. 531-5. ILLUSTRATIONS OF CRUCIFER.E (SHEPHERD'S PURSE). 



FIG. 532. 



FIG. 533. 



Fig. 531. Vertical section of flower. Magnified. 



Fig. 532. Pistil and stamens. Magnified. 



Fig. 533. Ripe capsule spli ting open. Magnified. 



Fig. 534. Seeds on placentie, the capsule-valves removed. Magnified. 



Fig. 53d. Cross-section of capsule. Magnified. 



probably the original form from which have been derived by long cul- 

 tivation the following races, which are now almost, if not quite, entitled 

 to be regarded as species, differing as they do fully as much from one 

 another as many wild species : 



Race I. Cauliflower, in which the thickened and consolidated flower 

 peduncles constitute the edible portion of the plant. 



Race II. Pore Cole or Kale, in which the expanded but tender leaves 

 of the tall stem are the edible parts. 



Race III. Brussels Sprouts, resembling the last, but with thick edi- 

 ble buds in the axils of the leaves. 



Race IV. Cabbage, in which the leaves do not expand, but form a sin- 

 gle large thick edible bud or " head." 



