Gramineae 93 



19. GRAMlNEAE Juss. Grass Family 



[Hitchcock. Manual of the Grasses of the United States. 1040p. 1096 

 fig. 1935. Deam. Grasses of Indiana. 356p. 81 pi. 1929.] 



The sequence of genera, nomenclature, and concept of species are those 

 of Hitchcock, "Manual of the Grasses of the United States." In a few in- 

 stances, however, where a named form of a species is distinct in Indiana 

 and is not given in Hitchcock's Manual, it is added here in the belief that 

 it will be appreciated by students who are making an intensive study of 

 the grasses. 



It is to be noted that the numbers of the genera are not consecutive; 

 this is because they are the ones used in Hitchcock's Manual. For the 

 benefit of students who prefer to follow the sequence of genera as they 

 occur in Dalla Torre and Harms' General Siphonogamarum, those numbers 

 are also added, following the number used in Hitchcock's Manual. 



KEY TO THE TRIBES 



Plants woody, culms perennial 1. Bambuseae, p. 94. 



Plants herbaceous, culms annual. 



Spikelets 1-many-flowered, 1 terete or laterally compressed; sterile lemmas or in- 

 completely developed florets above the fertile ones, except in Uniola and the 

 Phalarideae, in each of which the spikelet has at least 3 florets, the lower 2 

 sterile or rudimentary, and in Arrhenatherum, which has 2 florets, the upper 

 perfect, the lower staminate. 

 Glumes present, rarely one of them obsolete. 



Spikelets 3-flowered in plan, the uppermost floret perfect, the lower 2 staminate 

 or represented by sterile lemmas, which may be reduced to minute scales. 



7. Phalarideae, p. 144. 



Spikelets 1-many-flowered, no incomplete florets below the perfect ones, except 



in Uniola, Phragmites, and Arrhenatherum, none of which has spikelets 



3-flowered in plan. 



Inflorescence of spikes or racemes, either solitary, digitate, racemose, or the 



spikelets never long pedicellate. 



Spikelets solitary or in clusters of 2-6, alternate on opposite sides of the 



axis; spike solitary, terminal 3. Hordeae, p. 113. 



Spikelets in 1-sided spikes or racemes, the spikes or racemes solitary or 



several 6. Chlorideae, p. 141. 



Inflorescence a panicle, open or contracted, sometimes spikelike. 



Spikelets 1-flowered 5. Agrostideae, p. 125. 



Spikelets 2-many-flowered. 



Glumes shorter than the lowermost floret (see also Sphenopholis) ; lemmas 

 usually awnless, if awned, the awn terminal or from a minutely 



bifid apex 2. Festuceae, p. 95. 



Glumes at least as long as the lowermost floret (shorter in Sphenopholis) ; 

 lemmas awnless or with the awn attached to the back or from a bifid 



apex 4. Aveneae, p. 121. 



Glumes obsolete. 



Flowers perfect, each having a pistil and at least 1 stamen. .8. Oryzeae, p. 145. 



Flowers imperfect, staminate and pistillate flowers in different spikelets 



9. Zizanieae, p. 146. 



1 Spikelets of Panicum are apparently 1-flowered but examination shows them to be structurally 2- 

 flowered. The upper flower is fertile and the lower one is represented usually only by a lemma which is 

 the outer or loose one of the spikelet. 



