Upham.] 
166 
[May 21, 
leaves, etc., from the preceding, and I have observed no intergra- 
dation between these species. 
Polygonum Pennsylvanicum, L., frequent or common in moist, 
waste places, especially southward. 
Polygonum Persicaria , L. (Lady’s Thumb), habit like the last; 
becoming introduced and spreading with settlements westward. 
Polygonum Hydropiper, L. (Common Smartweed or Water-Pep- 
per) , indigenous, often growing in moist woods ; also a frequent 
weed of roadsides and wet pastures.' 
Polygonum Convolvulus, L. (Black Bindweed ), a bad weed of 
cultivated ground ; especially troublesome in fields of grain by caus- 
ing it, when beaten down by wind and rain, to remain so. 
Euphorbia maculata, L. (Spotted Spurge), frequent, usually 
growing as a weed of roadsides, dooryards, and waste places, pre- 
ferring sandy soil. 
Cannabis sativa , L. (Hemp), a common or frequent weed in 
waste places of towns. 
Urtiea gracilis, Ait. (Tall Wild Nettle), frequent or common in 
rich soil, along fences and near dwellings, especially on bottomlands 
of rivers or near woods ; indigenous westward to the Rocky Moun- 
tains and north to the Mackenzie river. 
Panicum capillare, L. (Old-witch Grass), common on cultivated 
ground and in waste places, especially on sandy alluvial bottom- 
lands. 
Panicum Crus-galli , L. (Barnyard Grass), common in moist 
rich soil, especially in barnyards and along roadside ditches near 
dwellings. 
Setaria glauca, Beauv. (Foxtail), and S. viridis, Beauv. (Green 
Foxtail) , both called “ Pigeon Grass,” are becoming common, spread- 
ing westward, in cultivated ground and waste places. 
Muhlenbergia glomerata, Trin., vaf. rarnosa, Vasey, abundant 
in deserted fields near Red Lake Agency, Minnesota ; often plenti- 
ful on cultivated ground in Pembina county, North Dakota. 
Avena fatua, L. ( Wild Oats), rare in Minnesota, more frequent 
in Manitoba, growing in grain-fields and on waste ground ; becom- 
ing very troublesome in oat-fields in Wisconsin. 
Eragrostis major , Host, abundant in dooryards and by roadsides 
throughout the south half of Minnesota and in the Red river val- 
ley. [It was found byGeyer in 1839 on sandy plains in the valley 
