THE GRASS FAMILY. 25 



35. Scales two — styles two, 36— Festuca. 



35. Scales and styles three, 40— Arundinaria. 



36. Panicle contracted, 37 



36. Panicle large diffuse 30— Melioa. 



37. Lower palea one-pointed, or muoronate, 38 



37. Lower palea pointless, 29— Eatonia. 



37. Lower palea three-cleft, 24 Tricuspis. 



37. Lower pale awnless, 25— Dupontia. 



38. Stamens three, 28— Kceleria. 



38. Stamens two, 26— Diarrhena. 



39. Spikelets two-ranked, 37 



39. Spikelets unilateral 43 



40. Glumes broad, 41 



40. Glumes subulate 42 



40. Glumes none, 46 — Gymnostichum. 



41. Glumes two, in the upper spikelet only, 42 — Lolium. 



41. Glumes two, in each spikelet, 43 — Triiicum. 



42. Glumes collateral, spikelets in twos or more, . . 46 — Elymus. 



42. Glumes opposite, spikelets solitary 45 — Secalc. 



43. One perfect among several neutral ones 17 — Ctenium. 



43. ' One perfect flower below several neutral ones, 44 



48. Spikelets conglomerate, or paniculate, 27 — Dactylis. 



43. Spikelets with more than one perfect flower 45 



44. Spikes dense, s- ■ • 18 — Bouteloua. 



44. Spikes filiform, racemed, 19 — Gymnopogon. 



44. Spikes slender, digitate, 20 — Cynodon. 



45. Spikes digitate, glumes and pale awnless, blunt 22 — Eleusine. 



45. Spikes racemed, slender, 23 — Leptochloa. 



The order Grajiine^, or the Grass Family, embraces, 

 as already said, plants with cylindrical stems, for the 

 most part hollow, and closed at the joints, with leaves 

 in two alternate rows, and sheaths open on the side 

 opposite the blade, down to the point from which Ihey 

 start. The flowers are in little spikelets held in two- 

 rowed glumes or bracts, the outer glumes generally 

 two in number, and unequal. The stamens vary from 

 one to six, but are usually three, in number. The 

 ovary is simple, with two styles and two feathery stig- 

 mas; and the fruit is enclosed in a husk, called a cary- 

 opsis. This great and universally diffused order is 

 divided by botanists into tribes, sub-tribes, genera, 

 3 



