SPERMATOPHYTES 



137 



Angiosperms whose flowers contain only one kind of sporo- 

 phyll. This means that such plants have two kinds of flowers, 

 one containing stamens, and the other containing carpels. 

 These two kinds of flowers may be produced by the same 

 plant or by different plants. In the latter case, there are 

 two kinds of sporophytes, differing in their flowers, one kind 

 bearing staminate flowers 

 (with stamens only), and 

 the other kind bearing car- 

 pellate flowers (with car- 

 pels only). For example, 



FIG. 108. Section of a flower of 

 Althaea, showing sepals (a), petals 

 (6), tube of stamens (c) inclosing 

 the style (d), and also the ovules 

 (e) within the ovary. After BERG 

 and SCHMIDT. 



FIG. 109. Indian corn (maize) : A, 

 showing the "tassel" (made up of 

 staminate flowers) ; B, showing the 

 ear (made up of carpellate flowers) 

 within its husk and the exposed "silk" 

 (made up of the long, protruding 

 styles). After DEVRIES. 



the corn plant has the two kinds of flowers, but both are 

 borne by the same individual (sporophyte), the staminate 

 flowers forming the " tassel " and the carpellate flowers 

 the " ear " (Fig. 109) ; while in the chestnut, one tree 

 bears staminate flowers (and therefore does not produce 

 chestnuts) and another tree bears the carpellate flowers. 



83. The carpel. It has been stated that the term " carpel" 

 has been applied among Seed-plants to the structure called 



