XVIIl] 



MARE'S-TAIL 



231 



- a.l. 



(\z 



-rii 



---w.l. 



Fig. 151. Hippuris vulgaris, L. A, shoot showing air leaves (^./.), water leaves 

 {w.l.) and roots (r.). Whorls of flowers at the upper nodes; Wj, node with flowers 

 whose anthers have dehisced; n.^, node with flowers whose anthers are still closed. 

 B, whorl of flowers enlarged, leaves (/) cut away. C, a single flower seen from 

 adaxial side; st = feathery style; an = anther; ovary. (Reduced.) [A. A.] 



