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..
Panicum capillare var. flexile Gattinger, Tenn. Fl. 94. 1887.
Culms erect, 6'-2 tall, rather stiff, slender, simple or somewhat branched at base, bearded at the nodes. Sheaths papillose-hispid; blades 4-9' long, 2"-3" wide, erect, long-acuminate, pubescent or almost glabrous; panicle 4'-9' long, narrowly ovoid to oblong in outline, its branches ascending, the lower ones 2'-3 1/2' long; spikelets 1 1/2"-1 3/4" long, single on the ultimate divisions of the panicle, acuminate; first scale one-fourth to one-half as long as the spikelet; second and third scales about equal, 5-7-nerved, about one-third longer than the fourth scale.
In moist or dry soil, Ontario to South Dakota, south to ' Florida and Texas. Aug.-Oct.
Panicum miliaceum L. Sp. PI. 58. 1753.
Culms erect or decumbent, rather stout, 1° or more tall, glabrous or hirsute. Sheaths papillose-hispid; blades 5'-10' long, 1/3'-1' wide, more or less pubescent; panicle rather dense, 4'-10' long; branches erect or ascending; spikelets 2" -2 1/2" long, acuminate; first scale about two-thirds as long as the spikelet, acuminate, 5-7-nerved; second scale 2"-2\" long, acuminate, 13-nerved, somewhat exceeding the 7-13-nerved acuminate third one, which subtends an empty palet; fourth scale shorter than the third, becoming indurated, obtuse.
In waste places, Maine to Florida, Michigan and California. Adventive from the Old World. July-Sept.
Panicum amarulum Hitchc. & Chase, Contr. U. S. Nat. Herb. 15: 96. 1910.
Smooth and glabrous, glaucous, the tufted culms 1 1/2°-4 1/2° tall; sheaths overlapping; blades 6'-1° long, 3"-6" wide, long-acuminate, thick and leathery, involute on the margins, at least toward the apex, the uppermost leaf exceeding the panicle; panicle contracted, 1°-2 1/2° long, its branches erect; spikelets about 2 1/4" long; the first scale one-half to two-thirds as long as the spikelet, the third somewhat longer than the second, usually with a palet and staminate flower, the fourth elliptic, about 1 3/4" long.
Panicum amaroides Scribn. & Merr. Circ. U. S. Dep. Aer. Agrost. 29: 5. 1901.
Glaucous and glabrous. Culms scattered, 1 1/2°-3° tall, from a stout creeping rootstock; leaves thick and firm; sheaths overlapping; blades up to 1° long, 3"-5" wide, flat, or involute toward the apex; panicle 6'-1 1/2° long, contracted, narrow, the short branches appressed; spikelets 2 1/2"-3" long, commonly broad and stout, the first scale more than i as long as the spikelet to nearly equalling it, the second and third scales about equal, all acute.
In sands along the coast, Connecticut and Long Island to Florida and Mississippi. Aug.-Oct.