OF TENNESSEE. 67 



15 Flowers stalked 7 Agrostis 



15 Flowers sessile 5 Vilf a 



16 Flowers awned , 17 



16 Flowers without awns 22 



17 Spikes solitary 18 



17 Spikes many, awnless, unilateral, palese cartilaginous. ..59 Panicum 

 IV Spikelets two, fertile 63 Erianthus 



17 Spikes two, polygamous, sterile, flowers bearded 6i Andropogon 



18 Spikes simple or nearly so , 19 



18 Spikes paniculate, or lobed 21 



19 Involucre none 20 



19 Involucre of two or more bristles 60 Setaria 



19 Involucre burr-like 61 Cenchrus 



20 Palese with awns one to three times their length 3 Alopecurns 



20 Palese with awns five times their length 44 Hordeum 



21 Both glumes and palese awned 10 Muhlenbergia 



21 Glumes awnless, single palese awned 54 Anthoxanthum 



21 Palese two, lateral flowers staminate,. 53 Hierochloa 



22 Flowers perfect or polygamous 23 



22 Spikes monoecious 25 



23 Spikes one-sided , . . , . . 24 



23 Spikes cylindrical, solitary terminal 4 Phleum 



24 Spikes two or more, spikelets suborbicular 58 Paspalum 



24 Spikes digitate or verticillate, linear 59 Panicum 



24 Spikes pedunculate, in a two-sided paniple 16 Spartina 



24 Spikes sessile, in a one-sided panicle 41 Lepturus 



25 Spikes all terminal, sterile above, fertile at base 62 Tripsacum 



25 Fertile spikes lateral, sterile ones terminal panicled 66 Zea 



26 Inflorescence in panicles '. 27 



26 Inflorescence in spikes 39 



27 Flowers awned 28 



27 Flowers without awns S3 



28 Lower palese awned on the back 29 



28 Lower palese awned on the apex 32 



2D Awn near the base of the palese 30 



29 Awn near tie apex of the palese 31 



30 Apex bifid, awn bent 50 Avena 



30 Apex bifid, awn bent, lower flower sterile 51 Arrhenatherum 



30 Apex multifid « 47 Aira 



31 Palese with two bristly teeth 49 Trisetum 



31 Palese bifid 37 BromuB 



32 Liwer pajf se rounded, obtuse 35 Briea 



82 Lower palese entire, pointed, fruit coated 36 Festuca 



82 Awn between two teeth, twisted 48 Danthonia 



