OF TENNESSEE. 67 



15 Flowers stalked 7 Agrostis 



15 Flowers sessile 5 Vilfa 



16 Flowers awned , , 17 



16 Flowers without awns 22 



17 Spikes solitary 18 



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

 17 Spikelets two, fertile 63 Erianthus 



17 Spikes two, polygamous, sterile, flowers bearded 64 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 



1 9 Inolucre burr-like 61 Cenchrus 



20 Paleae with awns one to three times their length 3 Alopecurus 



20 Paiese with awns five times their length 44 Hordeum 



21 Both glumes and paleae awned 10 Muhlenbergia 



21 Glumes awnless, single paleae awned 54 Anthoxanthum 



21 Paleae. 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 5,8 Paspalum 



24 Spikes digitate or verticillate, linear 59 Panicum 



24 Spikes pedunculate, in a two-sided panicle .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 33 



28 Lower paleae awned on the back 29 



28 Lower paleae awned on the apex 32 



29 Awn near the base of the paleae 30 



29 Awn near the apex of the paleae ". 31 



30 Apex bifid, awn bent 50 Avena 



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



30 Apex multifid 47 Aira 



31 Paleae with two bristly teeth 49 Trisetum 



31 Paleae bifid 37 Bromus 



32 Lower paleae rounded, obtuse 35 Briza 



32 Lower paleae entire, pointed, fruit coated 36 Festuca 



82 Awn between' two teeth, twisted 48 Danthonia 



