THE GRASS FAMILY. 25 



35. Scales two styles two, 86 Festuca. 



35. Scales and styles three, 40 Arundinaria. 



36. Panicle contracted, 37 



36. Panicle large diffuse, 30 Melica. 



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



37. Lower palea pointless, 29 Eatonia. 



37. Lower palea three-cleft 24 Tricuspis. 



37. Lower pale awnless, 25 Dupontia. 



38. Stamens three 28 Koeleria. 



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 Triticum. 



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



42. Glumes opposite, spikelets solitary, 45 Secale. 



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



43. One perfect flower below several neutral ones, 44 



43. Spikelets conglomerate, or paniculate, 27 Dactylis. 



43. Spikelets with more than one perfect flower, 45 



44. Spikes dense 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 GRAMINEJB, 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 they 

 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, 



