HITCHCOCK PLANTS OF A.^^ES, IOWA. 515 



R. VER riciLT.ATUs, L. Spec. 



Around ponds and ditches; abundant. 

 R. c'Hispus, L. Spec. 



Roadsides and waste places; common. 

 R. maritimus, L. Spec. 



Abundant on the borders of Cairo lake. 

 R. ACETOSELLA, L. SpCC. 



Pastures; infrequent. 

 Polygonum aviculare, L, Spec. 



Yards and roadsides ; common. 



In dry soil it is prostrate-spreading; in damp places, erect. 



P. ERECTUM, L. Spec. 



Roadsides ; common. 

 P. RAMOSISSIMUM, Michx. FI. 



Roadsides; frequent. 

 P. LAPATHiFOLiUM, L., var. iNCARNATUM, (Ell.) Watsou In Gray, 

 Man. 6th ed. — P. incarHutiim. Ell. Sk. i. 



Damp places; common. 

 P. Pennsylvakicum, L. Spec. 



Damp places: common. 

 P. amphibium, L. Spec. 



Ponds ; infrequent. 

 P. MuHLEXBERGii, Wats. Proc Amer. Acad. Sci. xiv. 1879. 



Low and often sandj soil ; abundant, 



I have not been able to satisfy myself that P. terrestre. (Willd.) B. S. P. Cat 

 (F. atnphibium. L., var. terrestre ,y^\\\A. Spec, ii.) should be used. 



P. Hartwrightii, Gray, Proc. Amer. Acad. viii. 1870. 



Ponds or even on sandy banks; becoming scarce. 

 P. orientale, L. Spec. 



Neglected ground. Ames. 

 P. Persicaria, L. Spec. 



Damp places; common. 

 P. Hydropiper, L. Spec. 



Wet places ; common. 

 P. ACRE, HBK. Nov. Gen. & Sp. ii. 1817. 



Wet places ; common. 

 P. ViRGTXIANUM, L. SpeC. 



Woods ; frequent. 

 P. Convolvulus, L. Spec. 



Cultivated grounds, especially stubble; common. 

 P. DUMETORUM, L., var. SCANDENS, (L.) Gray, Man. 5th ed.— P. 

 scandens, L. Spec. 



Thickets; common. 

 Fagopyrum esculentum, Moench, Meth. 1794. 



Cultivated ground ; frequent. 



