No. 17.1 



AGRICULTURAL COLLEGE. 



117 



Prince's Feather. 

 Polygonum. 

 Lady's Thumb. 

 Smartweed. 

 Water Persicaria. 



Knotgrass. 

 Larger Knotgrass. 



Black Bindweed. 



Climb'g False Buck- 

 wheat. 



Buckwheat. 

 Pale Dock. 

 Curled Dock. 

 Sheep Sorrel. 



POLYGONACE.E. 



Polygonum orientale, L. 



Ames. 



Polygonum Pennsylvanicum, L. 



Ames. 



Polygonum Persicaria, L. 



Ames ; Burlington. 



Polygonum Hydropiper, L. 



Ames ; Burlington. 



Polygonum amphibium, L., var. terrestre, Willd. 



Ames. 



Polygonum Virginianum, L. 



Ames. 



Polygonum aviculare, L. 



Ames ; Burlington. 



Polygonum ramosissimum, Michx. 



Ames. 



Polygonum Convolvulus, L. 



Ames ; Burlington. 



Polygonum dumetorum. L. (?) 



Grinnell. 



Fagopyrum esculentum, Moench. 



Ames. Escaped from cultivation. 



Pumex Britannica, L. 



Pumex crispus, L. 



Ames ; Charles City. 



Eumex Acetosella, L. 



Ames. Lately introduced from the East, where it is abundant 

 in sterile and worn fields, as on unwelcome weed. 



SANTALACE.E. 



Bastard Toad-flax. 



Comandra umbellata, Nutt. 



Ames ; Charles City ; Grinnell ; Burlington. 



EUPHORBIACE.E. 



Spurge. 



Euphorbia serpyllifolia, Pers. 



Ames ; Charles City. 



