This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Culms 1°-2 1/2° tall, erect or ascending, rigid, simple, smooth and glabrous. Sheaths overlapping, smooth, glabrous or villous, the upper one often enclosing the base of the panicle; ligule a ring of hairs; blades 5'-12' long, 2"-4" wide, smooth beneath, scabrous above and sparingly villous at the base; panicle 6-24' in length, purple or purplish, the branches 3'-10' long, strongly bearded in the axils, widely spreading or the lower often reflexed; spike-lets 5-15-flowered, 1 1/2"-4" long, on pedicels of at least their own length; scales acute, the empty ones about equal, the flowering ones about 7/8" long, their lateral nerves very prominent.
Poa refracta Muhl. Gram. 146. 1817.
Culms 1°-3° tall, erect, slender, simple, smooth and glabrous. Sheaths overlapping, smooth and glabrous; ligule a ring of short hairs; blades 5-12' long, 1 "-2" wide, smooth beneath, rough above, and villous toward the base; panicle 8'-2o' long; branches slender, 4-10' long, at length widely spreading, the axils often bearded; spikelets 6-25-flowered, 2 1/2"-6" long, on pedicels shorter than themselves; empty scales acute, the first somewhat shorter than the second; flowering scales very acute, 3/4"-1" long, the lateral nerves prominent.
In sandy soil, Delaware and Maryland to Florida, west to Texas. Aug.-Sept.
Eragrostis curtipedicellata Buckley, Proc. Acad. Phila. 1862: 97. 1862.
Culms 6'-3° tall, erect, rigid, simple, smooth and glabrous. Sheaths overlapping, smooth, pilose at the summit; ligule a ring of short hairs; blades 2'-%' long, \"-2" wide, smooth beneath, scabrous above; panicle 4'-12' in length, the branches widely spreading, 1 1/2'- 4 1/2' long; spikelets 5-12-flowered, 1 1/2"-3" long, on pedicels of less than their own length; scales acute, the empty ones somewhat unequal, the flowering ones about 7/8" long, scabrous on the midnerve, their lateral nerves prominent.
Prairies, Kansas to Texas. Aug.-Sept.
Culms 2°-4° tall, erect, simple, smooth and glabrous. Sheaths overlapping, smooth, pilose at the throat; ligule a ring of very short hairs; blades 6'-28' long, 1 "-2" wide, smooth beneath, slightly scabrous above, attenuate into a long slender tip; panicle 9'-26' in length, narrow and elongated, the branches erect or ascending, capillary, subdividing, somewhat flexuous, 3'-7' long; lower axils sometimes bearded; spikelets usually pale, 3-10-flowered, 2 1/2"-4 1/2" long; lower scales very acute, about equal; flowering scales acute, the lower ones 1 1/4"-1 1/2" long, their lateral nerves manifest.
In dry sandy soil, Illinois to Nebraska, south to Texas. Blow-out-grass. Aug.-Sept.