288 



FLOWERS 



times, however, the anther is attached near its middle and 



swings free at both ends. 



There is a good deal of variation in the way in which 



the pollen sacs open. The most common way is by a 



lengthwise slit. Some- 

 times, however, the slit 

 is only at the top of the 

 anther, and sometimes 

 the pollen is discharged 

 through a round pore. 

 (See Figure no.) There 

 are still other variations 

 in this feature of the 

 andrcecium. 



Stamens vary as to 

 where they are attached 

 to the rest of the flower. 

 In flowers with separate 

 petals they are usually 

 attached to the recep- 

 tacle like the other 

 parts, but in flowers 

 with united petals it is 

 common to find them 

 attached to the corolla. 

 (See Figures loy and 

 III) 



Sometimes the sta- 

 mens are not all alike. 



A striking case of this is found in the sweet pea. In its 



flower you find nine stamens united and one which is free. 



A similar arrangement is found in the flower of clover. 



Fig. log. — Flowers of a mint (Slachys). 

 These flowers are irregular, tliat is, zygomor- 

 phic. See context. 



