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..
S. indicus Nash, in 111. Fl. Ed. 1, 1: 154. 1896. Not. R.
Glabrous and smooth throughout, culms 1°-4° tall, erect, tufted, simple or rarely sparingly branched. Sheaths few, long, shorter than the internodes; ligule a ring of very short hairs; blades 1"-3" wide, attenuate into a long slender point, the lower 8'-1° long, the upper shorter; panicle 4'-15' in length, usually elongated, narrow, spike-like; spikelets 3/4"-1" long, the outer scales unequal, about half as long as the third, obtuse, smooth and glabrous, the lower one shorter and often erose-truncate; third scale acute, somewhat exceeding the obtuse or acutish palet.
Agrostis virginica L. Sp. PI. 63. 1753.
Sporobolus virginicus Kunth, Rev. Gram. I: 67. 1829.
Culms 6'-2° tall, erect or sometimes decumbent, simple or branched at the base, smooth and glabrous. Sheaths numerous, short, overlapping and crowded at the lower part of the culm, smooth, glabrous or sometimes pilose on the margins and at the throat; ligule a ring of short hairs; blades 1'-8' long, 2" wide or less at the base, distichous, acuminate into a long point, involute on the margins and at the apex, smooth beneath, scabrous above or sometimes sparingly hairy; panicle 1'-3' long, 2"-5" thick, dense and spike-like, usually exserted; spikelets 1"-1 1/4" long, the outer scales about equal, acute, smooth and glabrous; third scale smooth and glabrous, acute, slightly shorter than the second and about equalling the obtuse palet.
On sandy shores, Virginia to Florida, Texas, Mexico and South America. West Indies. Aug.-Sept.
Culms tufted, 4'-12' tall, slender; blades 2' long or less, not over 3/4" wide; panicle open, 1'-8' long, its slender branches spreading or ascending; spikelets about 1 1/4" long, on capillary pedicels which are abruptly thickened at the apex, the empty scales shorter than the flowering scale, glabrous or pubescent, the flowering scale usually pubescent.
Usually in wet places, Montana and Nebraska to Mexico. June-Sept.
Poa uniflora Muhl. Descr. Gram. 151. 1817. Agrostis serotina Torr. Fl. U. S. 1: 88. 1824. Sporobolus serotinus A. Gray, Man. 577. 1848. S. uniflorus Muhl.; Scribn. & Merr. Circ. U. S. Dep. Agr. Agrost. 27: 5. 1900.
Glabrous and smooth or very nearly so, culms 6'-18' tall, from an annual root, erect, slender, simple. Sheaths short, confined to the lower part of the culm; ligule less than 1/2" in length, irregularly truncate; blades 1/2" wide or less, slightly scabrous above, flat, the basal one-third to half the length of the culm, those of the culm 2'-4' long; panicle 3'-9' in length, the branches capillary, erect or ascending, the lower 1'-2 1/2' long; spikelets about 5/8" long, the outer scales subequal, obtuse, smooth or sometimes sparingly scabrous; third scale twice the length of the outer ones, acuminate.
In wet sandy soil, Maine to Ontario and Michigan, south to New Jersey. Sept.-Oct.