154 



ESSENTIALS OF BOTANY 



Fig. 110. Monadel- 



phous Stamens of Fig. 111. Diadelphous 

 Mallow. Stamens of Sweet Pea. 



cases or chambers, in which the ovules are forriled, and 

 which are generally quite closed. 



183. The Pistil. — The term pistil (Latin for pestle) is 

 applied to the closed structure which contains the ovules 

 and is formed by the carpels of the 

 angiosperms. This is a more general 

 term than carpel, for it applies to organs 

 composed of one or of several carpels. 

 If one-carpeled, a pistil is said to be 

 simple; if of two or 

 more carpels, it is 

 compound. 



The _ pistil often 

 consists of the parts 

 shown in Fig. 112, 

 an enlarged hollow portion containing ovules and known 

 as the ovary, a stalk-like style, and a knob sUg—c:^ 

 or ridged expansion called the stigma. 

 Not infrequently the style is wanting and 

 the stigma is sessile (seated) on the ovary. 

 A flower may contain a large number 

 of carpels in the form of simple pistils 

 entirely separate from one another, as in 

 the buttercup and the stonecrop (Fig. 98). 

 When several carpels form a compound 

 pistil, the manner and extent of the union 

 is various. The union generally forms the 

 ovary, although this is sometimes developed ""' °^^^ • f ''-'' ^*y'® '• 



. 1 , *''?' stigma. 



in large part as a cuplike or tubular growth 

 under the carpels. Sometimes the union is complete, so that 

 the compound pistil has only one style and stigma. But 

 frequently the styles remain separate, or the styles may be 



Fig. 112. Parts 

 of the Pistil. 



