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..
[Diarina Raf. Journ. Bot. 2: 169. 1809.]
Erect grasses, with long flat leaf-blades and narrow paniculate or racemose inflorescence. Spikelets 3-5-flowered, the rachilla readily disarticulating between the flowers. Upper scales empty, convolute. Two lower scales empty, the first narrow, 3-nerved, acute, the second broader, 5-nerved; flowering scales broader than the lower ones, acuminate or mucronate, rounded on the back, finally coriaceous and shining, 3-nerved. Palet 2-keeled. Stamens 2, rarely 1. Styles short, distinct. Stigmas plumose. Grain beaked, free. [Greek, in allusion to the beaked grain.]
Festuca diandra Michx. Fl. Bor. Am. 1: 67. pl. 10. 1803. Not Moench, 1794. Korycarpus arundinaceus Zea, Act. Matrit. 1806. Diarrhena americana Beauv. Agrost. 142. pl. 25. f. 11. 1812. Korycarpus diandrus Kuntze, Rev. Gen. PI. 772. 1891.
Culms 1 1/2°-4° tall, erect, simple, very rough below the panicle. Sheaths overlapping, confined to the lower part of the culm, smooth or a little rough at the summit, sometimes pubescent; ligule very short; blades 8'-24' long, 5"-9" wide, long-acuminate at the apex, usually scabrous; panicle often reduced to a raceme, 2'-7 1/2' in length, the branches erect, 1'-2' long; spikelets 3-5-flowered, 6"-8" long, the lower scales unequal, the first shorter than the second, which is much exceeded by the spikelet; flowering scales somewhat abruptly acuminate; palets shorter than the scales and exceeded by the beaked grain.