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PAPERS ON BOTANY 139 
ored to gray, bobbin like, surface marked by vertical lines; 2 
to 2.5 mm. long. In grass, red clover and alfalfa. Plate VI. 
BROMUS SECALINUS. Cheat, Chess. Grain or caryopsis, red- 
dish brown, somewhat spindle shaped, vertical groove on one 
side to which is often attached a row of bristles; 6 to 7 mm. 
long. Impurity of wheat 4nd red clover. Plate V. 
Potyeonacnan. Buckwheat family. 
Rumex crispus. Curled dock. Yellow dock. Narrow-leaved 
dock. Achene brown, shiny, three sided, apex attenuate; 1.5 to 
2 mm. long and 1.3 mm. in diameter half-way between base and 
apex. Common impurity in red clover, alfalfa and grass seed. 
Plate IT. 
RuMex oprusirotius. Broad-leaved dock. Bitter dock. 
Achene dark brown, three sided, very attenuate at apex; 2 to 2.5 
mm. long and 1 to 1.3 mm. in diameter half way between base 
and apex. In red clover and alfalfa. Plate II. 
Rumex Acprosetya. Field sorrel. Sheep sorrel. Redtop 
sorrel. Achene not easily freed from reddish brown calyx. 
Three sided, angles rounded, abruptly pointed at apex; 1 to 1.5 
mm. long. In clover, alfalfa and grass seed. Plate II. 
PotyGconum ConvotyuLus. Black bindweed. Wild buck- 
wheat. Achene black, three sided, angles rounded, concave 
sides; 3 mm. long and 2 mm. in diameter half way between 
base and apex. Common in red clover, barley and oats. 
Plate II. 
PoOLYGONUM PENNSYLVANICUM. Pennsylvania smart-weed, 
Pennsylvania persicaria. Achene jet black, lenticular, surface 
finely granular, short abrupt apex; 2.5 mm. short diameter and 
3mm. long diameter. Common impurity of red clover. Plate I. 
CHENOPODIACEAE. Goosefoot family 
CHENOPODIUM ALBUM. Smooth pigweed. Lamb’s quarters. 
Pigweed. White goosefoot. The seed when deprived of its 
covering, which is the calyx and the wall of the utricle, appears 
black. If this covering is not removed, it appears gray. Some- 
what lens-shaped, a groove extending nearly half way from edge 
to center; 1.5 to 1.8 mm. in diameter. Often in clover, alfalfa, 
and grass seed. Plate V. 
