52. Phragmites. Spikelets 3–7-flowered, lowest flower naked, staminate or neutral. Glume entire.

53. Arundo. As n. 52, but flowers all perfect. Glume bifid.

[*][*][*] Glume 3-nerved, the nerves (at least the mid-nerve) excurrent; spikelets few, in the axils of floral leaves.

54. Munroa. Low or prostrate much-branched annual.

[*][*][*][*] Glume 3- (rarely 1-) nerved, obtuse or acute, awnless; rhachis and flower naked.

55. Kœleria. Panicle contracted. Spikelets 2–4-flowered. Glumes compressed-keeled, acute or mucronate.

56. Eatonia. Panicle slender, more or less dense. Spikelets 2-flowered. Glumes very dissimilar, usually obtuse, the upper empty one enclosing the flowers.

57. Eragrostis. Spikelets flattened, 2–many-flowered. Glumes acute or acutish. Palet persistent.

[*][*][*][*][*] Glume 3–5-nerved, obtuse or abrupt-cuspidate; spikelet 3–5-flowered; upper sterile flowers convolute around each other.

58. Melica. Glumes 5-nerved or more, scarious, obtuse. Panicle simple or nearly so.