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..
P. Ashei Pearson, Journ. E. Mitch. Sci. Soc. 15: 35. 1898.
Culms tufted, 8'-16' tall, erect, usually sparingly branched, rarely much-branched and prostrate, pu-berulent; sheaths puberulent, usually less than 1/2 as long as the internodes, ciliate on the margin; blades 2-3' long, rarely longer, 3"-5" wide, occasionally broader, somewhat cordate at the base, erect or ascending, sometimes spreading, lanceolate, sparsely ciliate at the base with long hairs; panicle 2'-3' long, its branches ascending; spikelets about 1 1/4" long and 1/2" wide, elliptic, obtuse, pubescent with rather long weak hairs.
Culms erect, 16'-2 1/2° tall, rather slender, glabrous, puberulent at the nodes, simple, finally dichotomously branched above. Sheaths ciliate on the margin, and pubescent at the apex, otherwise glabrous; blades spreading or ascending, cordate and clasping at the base, 2'-5' long, 1/4'-1' wide, ciliate at the base, glabrous or puberulent, those of the branches generally broader and more crowded than those of the main stem; panicle 2'-5' long, lax, the branches spreading; spikelets 1 1/4" to nearly 1 1/2" long, elliptic; second and third scales equal, 7-nerved, pubescent; fourth scale oval, obtuse, apiculate, about 1" long.
In dry woods and thickets, Massachusetts to Missouri, Florida and Texas. June-Aug.
Culms tufted, 16-30 tall, glabrous or minutely puberulent below; sheaths glabrous, excepting the ciliate margin; blades 2 1/2'-5' long, 10"-20" wide, horizontally spreading, conspicuously ciliate, especially the broader ones at the base, glabrous on the surfaces; panicle 3'-6' long and nearly as wide; spikelets about 1 1/2" long, elliptic, pubescent, the first scale 1/3-1/2 as long as the spikelet.
In sandy soil, southeastern Virginia to Florida and Mississippi. June and July.
P. latifolium L. Sp. PI. 58. 1753.
Culms 1°-3° tall, erect, simple, later somewhat branched above, smooth; the nodes, at least the upper ones, naked. Sheaths smooth and glabrous, excepting the pubescent ring at the apex and the ciliate margin; blades 3'-7' long, 9'-1 1/2' wide, cordate-clasping at base, acuminate, smooth and glabrous or nearly so on both surfaces, ciliate; panicle 3'-6' long, generally long-exserted, rarely included, its branches with few spikelets and more or less ascending; spikelets 1 1/2"-2" long, turgid, oval to obovoid; second and third scales broadly oval, obtuse, 9-nerved, pubescent, the fourth oval, rather acute, 1 1/2" long. In woods, Maine to Minnesota, south to North Carolina and Kansas. July-Aug.