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 the three families 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 (Papaveracez) 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 gynoecium which, unlike any in the crowfoot order (ex- 
cept possibly th 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 
placentz which lie along the outer wall of the compound 
