THE POPPY FAMILY 361 



always dehiscing by uplifted valves, constitute the chief mem- 

 bers of the family. 



108. The crowfoot order (Ranunculales or Ranales). A 

 comparison of tlie three famihes we have been studying shows 

 them to be closely linked together, much as are the genera 

 within each family. By such linkage there is formed a natural 

 chain of families including these and several others resembling 

 them in important respects. Such a group of families is 

 termed, as we have seen (page 8), an order. That which 

 clusters about the crowfoot family takes significantly the 

 name of the crowfoot order. 



The prevailing characters of Ranunculales are expressed in the 

 formula of the order given on pages 406, 407. 



Neglecting the more variable or exceptional features we 

 may say that the plants of this order, though differing widely 

 in habit, foliage, and inflorescence, are characterized by 

 having usually cymose inflorescences of mostly -perfect, regular, 

 and hypogynous flowers with well-developed perianth often in 

 whorls of three, stamens and, carpels usually numerous, and 

 all parts commonly distinct and free. 



109. The poppy family (Papaveraceae) is represented 

 sufficiently well for our purpose by the opium poppy (Papaver 

 somniferum, pages 182, 183). Like all the other species of its 

 genus, it contains instead of volatile oil a milky juice from 

 which, as we have seen, opium is obtained. Many other 

 genera of the family contain a similar juice which in some 

 cases is bright yellow, and in others red. Sometimes the 

 juice is watery. 



The main structural features of Papaver appear in its formula on 

 pages 406, 407. 



The only new features calling for special notice concern 

 the gjTioecium which, unlike any in the crowfoot order (ex- 

 cept possibly in the laurel family) , consists of several carpels 

 so united as to form a compound pistil with a one-celled 

 ovary. That is to say, the carpellary leaves as they grow 

 have the right edge of one coalescent with the left edge of its 

 neighbor. The united edges of neighboring carpels thus form 

 placentije which lie along the outer wall of the compound 



