28 



WEED FLORA OF IOWA 



spikelets chestnut colored, 3-flowered; the 2 lower flowers stamin- 

 ate with 3 stamens; the upper flower perfect, short pedicelled, 

 awnless, with 2 stamens. 



Distribution.- — Common in the north. Frequently a trouble- 

 some weed in Minnesota and northwest territory. Common only as 

 a weed in a few of the northwestern counties of Iowa. 



Extermination. — This weed can be exterminated by giving a 

 shallow plowing after the crop has been removed and stirring the 

 soil thus exposing the root-stocks to the action of the sun. 



Poverty Grass (Aristida dichotom,a Michx.). 

 Description.- — A slender, tufted, branched annual from 12-24 

 inches tall; spikelets in narrow, striate, simple or compound spikes; 



^'^'a^n^lrT^ °!^^\ ^'^'-^'*'^" M^^^otoma). Common in dry. sterile soil, 

 one Toned °' ^ splkelet; b, ^ floret showing awns, middle 



