lO 



ALISMACEAE 



[CH. 



to^ 



Fig. I. Sagittaria sagittifolia, 

 L. Top of inflorescence, August 

 17, 1917. (? = whorl of male 

 flowers; $ = whorl of female 

 flowers with withered perianths, 

 (f nat. size.) [A. A.] 



Fig. 2. Sagittaria sagittifolia, L. Top of 

 infructescence, September 8, 191 7. (f nat. 

 size.) ^ , Longitudinal section of fruit. [A. A.] 



