130 



INTRODUCTION TO BOTANY 



Stamens are often joined by their filaments so as to form 

 one, two, three (fig. 109), or several groups. In other cases 

 they are joined by their anthers into a single group which 

 surrounds the pistil (fig. 110). In the latter 

 case the pollen is often at length forced out 

 of the anther tube in a single mass by the 

 lengthening pistil (fig. 111). 



121. Carpel and pistil. Although the entire 

 flower is more or less engaged in the work 

 of seed production, it is the carpel (from a 

 Greek word meaning " fruit ") in which the 

 rudimentary seeds, or ovules, originate. In 

 its simplest form, as in the pines and related 

 trees, the 

 carpel con- 

 sists of a 

 scale of the 

 seed-bear- 

 ing cone (fig. 224). Each 

 young scale bears at its 

 base an ovule, or rudi- 

 mentary seed. Among the 

 higher flowering plants the , FIG. ill. A single 



carpel produces the ovules A-WWr flower of the hun " 



J dred or more which 



compose the head 

 of flowers of the 

 Canada thistle 



FIG. 109. Flower 

 of St.-John's-wort, 

 with the numerous 

 stamens in three 

 groups 



The sepals and petals 



have been removed. 



After Warming 



A/ 



FIG. 110. Stamens 



inside a cavity known as 

 the ovary (fig. 112). 



The carpellary portion 

 of the flower of the higher of a thistle, with 



seed plants (whether it con- anthers united into 



. , e , , a ring 



sists or one or more carpels) 



, . -i . . . 7 -,-, . a. united anthers ; /. 



IS known as the pistil Evi- filaments, bearded 



dently, if the flower has but on the sides - After 



one carpel (fig. 105), the 



words carpel and pistil as applied to such a flower mean the 



same thing. If there are several carpels, each is one of the 



units of which the entire pistil is built (fig. 102). A pistil 



a, the anthers united 

 to form a tube ; p, 

 the clump of pollen 

 grains forced out 

 from the anther tube 

 by the lengthening of 

 the pistil within the 

 tube. After H.Miiller 



