1 



118 TWELFTH ANNUAL REPORT. 



AMARANTACE.E. Amaranth Family. 



AMARANTUS, Tourn. Amaranth. 



A. retrojfexus, L. Pigweed. Red-root. 

 A common weed throughout the state. 



A. alhus, L. Tumble-weed. 



Frequent southeastward and hi the Red river valley ; abundant southwestwavd, on 

 both the longest cultivated and the newly broken land. (North of lake Superior, Agas- 

 siz; "sandy shore of the upper Missouri " [probably there indigenous, and perhaps so 

 in western Minnesota], Geyer.) The popular name alludes to the behavior of this plant 

 in autumn and winter, as described by A7'(/atr : "It grows in a globular form, often 

 three^or four fe<»t in diameter. When killed by frost, the branches remain rigid, the 

 plant soon loosens from the soil, and the wind drives it bounding over the fields and 

 prairies, until brought up in some fence corner. When the corner is full, those that 

 follow are enabled to scale the fence. With a change of wind, all the lodged plants 

 are set flying in another direction. This is an effective method of scattering the 

 seeds."— Prairie fires are sometimes carried by these rolling dead weeds across broad 

 fire-bi'eaks of plowed land. 



A. blitoides, Wiitson.* Amaranth. 



Mankato (a common weed by roadsides and in waste places), Lelberg; Martin 

 county, and in Emmet county, Iowa, (rare), Cratty. South. "It grows flat upon the 

 ground like purslane, and has a dark green, glossy leaf, not much larger than that of 

 purslane, but thinner. It is a native of the western plains, but is traveling eastward 

 as a weed. It is abundant in Iowa at Clear Lake and southward." Arthur. 



ACNIDA, L. Water- Hemp. 



A. tiiberculata, Moquin. (Montelia tamariscina, Gray, in part, and its var. 

 concatenata, Gray.) "Water- Hemp. 

 St. Croix river. Parry; common on gravelly shores of the Le Sueur and Minnesota 

 rivers in Blue Earth county, Leihery; also common in Martin county, and in Emmet 

 county, Iowa, C'rartj/. "Sometimes erect, and from one to four feet high; sometimes 

 spreading or prostrate." South. 



FRCELICHIA, Moench. Feoslichia. 



F. Floridana, Moquin. Frcelichia. 



Lapham. Minneapolis, Bobcrts. Rare. South. 



POLYCIONACE^. Buckwheat Family. 



POLYGONUM, L. Knotweed. Polygonum. 



P. viviparum, L. Alpine Bistort. 



Grand Marais, lake Superior, Roberts. North. 



base, semiterete, ^4 to l inch long, the floral ones oblong- to ovate-lanceolate or ovate, 

 acute, rather crowded : calyx cleft to the middle somewhat unequally, one or more of 

 the acute lobes strongly carinate or crested; seed vertical or horizontal, half a line 

 broad, very lightly reticulated. Watson, Botany of California. 



*AMARANrus BLiTOiDES, Watson. Prostrate or decumbent, the slender stems 

 becoming a foot or two long, glabrous or nearly so ; leaves broadly spatulate to nar- 

 rowly oblanceolate, attenuate to a slender petiole, an inch long or usually less ; flowers 

 in small contracted axillary spikelets ; bracts nearly a line broad. Proc. Amer. 

 Acad .\o\. xii. 



