complete flower displays four distinct kinds 

 of modified leaves, arranged in concentric 

 whorls, attached to a receptacle, which con- 

 nects the llower with its stalk (Fig. 12-14). 

 The outermost whorl, called the calyx, con- 

 sists of separate parts, the sepals (Fig. 12-14), 

 •which are usually leaflike in form and color. 

 Just inside the calyx lies the corolla, the 

 separate parts of which are called the petals 

 (Fig. 12-14). The petals also display a leaflike 

 form, but often they are brightly colored, 



Reproduction in Multicellular Pianis - 217 



especially in insect-pollinated species. The 

 petals and sepals are subject to endless varia- 

 tion in form, color, and number, and either 

 or both may be entirely absent, since they 

 play a very indirect role in reproduction. 



Just inside the petals are the microsporo- 

 phylls, which commonly are called the sta- 

 mens (Fig. 12-14). Each stamen consists of a 

 slender filament that bears an anther at the 

 upper end. Essentially the anther is a group 

 (usually of 2 or 4) of pollen capsules (micro- 



POLLEN 



CTGAMETOPHYTE 



MICROSPORES 

 FILAMENT 



PETALS 



PISTIL 

 OVULE CASE 

 MACROSPORE 



OVULE 



SEPAL 

 RECEPTACLE 



STIGMA^, 



UPON POLLINATION 



f CTGAMETOPHYTE 

 AT FERTILIZATION 



REMNANT OF STYLE 



ENLARGED WALL 

 OVULE CASE 



SEEDS 



REMNANT OF 

 PETALS & SEPALS 



RECEPTACLE 



FRUIT 



Fig. 12-14. Reproductive stages of flowering plants, showing relations between the flower, the fruit, and the 

 seed (see text). 



