280 



WEEDS AXD USEFUL TLAXTS. 



179 



4. P. Hydropi'per, L. Smooth, very acrid ; leaves lanceolate, pellucid- 

 (lotted, wavy margined ; sheaths ciliate with shortish bristles ; racemes 

 filiform, flaccid and nodding ; fascicles few-flowered, rather distant ; -lalyx 

 glandular-dotted. 



Fig. 179. The Penn.sylvaniaa rolygonum (P. Pennsylvanicum.) 180. An ev^w-a?'* 

 flower, opened. 



