Aristida oligantha Michx., old field threeawn 
DESCRIPTION 
Cool-season, annual. 
Height: 6 to 20 inches. 
Leaf blade: Flat; about 1/4 inch wide; rolls inward during 
hot, dry weather. 
Leaf sheath: Mostly basal. 
Seedhead: Loose, open panicle; glumes have 3 awns about 
1-1/2 to 3 inches long that curve at base. 
GROWTH CHARACTERISTICS 
Growth starts in early spring from seed. Life cycle is a month 
to 6 weeks. Oldfield threeawn is a good seed producer. Seedlings 
are vigorous. Sometimes called prairie threeawn. 
DISTRIBUTION 
Mostly in eastern half of United States ; some in Arizona, Cali- 
fornia, and southern Oregon. 
SITE ADAPTATION 
Grows mostly on areas such as old abandoned fields, oil-well lo- 
cations and cattle round-up grounds. 
USE AND MANAGEMENT 
Oldfield threeawn is practically worthless as a forage grass. 
After maturity, seed get in the wool of sheep and in the eyes of 
both cattle and sheep if they graze areas with a dense stand. This 
grass establishes easily under adverse conditions and protects soil 
against erosion until more desirable grasses take over. It is an in- 
dicator of deteriorated range condition. 
Range reseeding is the most practical and economical way to 
kill this grass and improve heavily infested ranges. Use perennial 
grasses adapted to the particular site. 
41 
