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..
Exp. Sta. 7: 34. 1894. Not P. pilosum Lam.
1791. Paspalum plenipilum Nash, in Britton, Man. 73. 1901.
A tufted pubescent perennial with flat leaf-blades and glabrous spikelets. Culms 1 1/2°-3 1/2° tall; leaf-sheaths tuberculate-hirsute with long spreading hairs, compressed; blades 1° long or less, 3"-5" wide, erect, hirsute on both surfaces with long spreading hairs; racemes 2-4, spreading or ascending, 2'-4' long, the rachis about 1/2" wide; spikelets singly disposed, oval, about 1 1/4" long and 1" wide, the outer 2 scales 5-nerved, the lateral nerves near the margin, approximate.
Paspalum circulare Nash, in Britton. Man. 73. 1901.
A tufted perennial with flat leaf-blades, and orbicular glabrous spikelets. Culms 1 1/2°-3 1/2° tall; leaf-sheaths tuberculate-hirsute with spreading or ascending hairs, compressed; blades erect, more or less hirsute on both surfaces, 1° long or less, 2 1/2"-4" wide; racemes 2-4, erect or ascending, 2 1/2'-4' long, the rachis about 1/2" wide; spikelets singly disposed, about \\" in diameter, their thickness about one quarter their diameter, the outer 2 scales thin and usually wrinkled when dry, 5-nerved, the lateral nerves near the margin and approximate, quite distinct.
In fields, New York to Missouri, south to North Carolina and Texas. July-Sept.
Paspalum pubiflorum glabrum Vasey; Scribn. Bull. Tenn. Exp. Sta. 7: 32. 1894.
Paspalum laeviglume Scribn.; Nash, in Small, Fl. SE. U. S. 75. 1903.
A stout glabrous perennial, usually rooting at the lower nodes, with flat leaf-blades, and glabrous spikelets. Culms 1 1/2°-4 1/2° tall, the nodes pubescent; leaf-sheaths glabrous, excepting the hirsute margins; blades 4'-16' long, 5"-10" wide, linear, glabrous on both surfaces; racemes 4-8, spreading or ascending, the lower ones commonly 2'-4' long; spikelets in pairs, 1 1/4"-1 1/2" long, about 1" broad, oval to broadly obovate, the first scale 3-5-nerved, the second 5-7-nerved.
In moist places, Maryland and Kentucky to North Carolina and Texas. June-Oct.
Paspalum virgatum Walt. Fl. Car. 75. 1788. Not L.
1810. Paspalum purpurascens Ell. Bot. S. C. & Ga. 1: 108.
A rather stout glabrous perennial with compressed culms, which often root at the lower nodes, flat leaf-blades, and glabrous spikelets. Culm 1 1/2°-4° tall; leaf-sheaths compressed, glabrous, or the basal ones hirsute; blades of medium texture, hirsute above near the base, linear, 1° long or less, 1 1/2" - 5" wide; racemes 2-13, spreading or ascending, 1 1/2'-4.' long, the straight rachis l"-l 1/4" wide; spikelets in pairs, i"-i 1/3" long, 3/4"-1" wide, broadly obovate, the first scale 5-nerved, the second 3-nerved.
In meadows and moist places, Virginia and Tennessee to Florida, west to Texas. Aug. and Sept.