MORPHOLOGY OF HIGHER PLANTS. 



377 



The pistil of the flower of the pea is simple and has an elon- 

 gated ovary, and upon dissecting the ovary and also making a 

 transverse section of it, it is observed that the ovules are borne 

 upon the part which projects from the concrescent margins into the 

 cavity, this part being known as the PLACENTA, and the united 



FIG. 219. Pistils and different kinds of stigmas. A, simple (monocarpellary) pistil 

 of willow with lobed stigma; B, compound pistil of Fourcroya with head-like stigma; C, 

 longitudinal section through flower of Spondias with five separate styles and stigmas, 

 only three of which are shown; D, flower of Peperomia showing bristly stigma; E, recurved, 

 thread-like stigmas of the Upas-tree (Antiaris} ; F, flower of a Canary grass showing the 

 two simple plumose stigmas; G, pistillate flower of couch grass showing the two compound 

 plumose stigmas; H, thread-like stigmas of pistillate inflorescence of EuMcena one of 

 the grasses; J, tri-parted stigmas of the pistillate flower of the castor-oil plant; K, L, 

 two forms of stigmas of Begonia. After Engler. 



margins of the carpel forming the " inner" or VENTRAL SUTURE. 

 In the syncarpous gynsecium the ventral suture of the carpels is 

 directed toward the axis of the flower ; in some cases that portion 

 of the carpel corresponding to the midrib is very prominent, as 

 in the Papilionatae, and has received the name of ' outer ' or 



DORSAL SUTURE. 



There are as many locules in the ovary as there are carpels, 



