CLASSIFICATION OF ANGIOSPERMS. 465 



FlG. 253. Arrow-head (Sagittaria latifolia), a common marsh or aquatic plant and 

 very widely distributed. The leaves are variable, but almost always sagittate. It produces 

 naked scapes which are sheathed by the bases of the petioles; the white flowers are produced 

 all summer. After Troth. 



30 



