KEY TO THE FAMILIES AND GENERA 



133 



208. CYPERACE^E. 



A. Fls. strictly unisexual; female inclosed in a 

 flask-shaped or bag-shaped scale or glume 



(perigynium) 1. Carex. 



AA. Fls. bisexual, rarely unisexual, not inclosed aa 



above. 

 B. With several (2 to many) of the lower 



-rules empty. 

 c. Spikelets few-fld. (usually 1-2-, rarely, 



3-G-fld. ) 2. Rhyncho- 



cc. Spikelets many-fld. [sporo. 



D. St. leafy 3. H ypoljtrurn. 



Dp. St. not leafy or only at base 4. Mapania. 



BB. With only 1 or 2 of the lower scales empty. 

 c. Scales 2-ranked. 



D. Perianth 5. Cyperua. 



DD. Perianth of 8 setae G. Dulichium, 



cc. Scales many-ranked, overlapping. 

 D. Perianth of 3-8, rarely 0, setae. 



E. Style persistent, thickened and bulb- 

 like at base 7. Eleocharia. 



EE. Style not or hardly thickened at base. 8. Scirpua. 

 DD. Perianth of many setae, very long- 

 excrescent after anthesis, becoming 

 wavy or cottony 9. Eriopkorum. 



209. GRAMINE^. 

 /. Summary of the Tribes. 



Subfamily I. PANICOIDE^. 



Spikelets 1-, rarely 2-fld.; the terminal fl. perfect, the lower 

 Btaminate or neuter; rachilla articulated below the glumes, the 

 more or less dorsally compressed spikelets falling from the 

 pedicels entire, singly, in groups, or together with joints of an 

 articulate rachis. 



A. Spikelets unisexual, the male and 

 female spikelets in different infl. on 

 the same plant or in different parts 

 of the same infl. ; awnless ........... 



AA. Spikclets perfect, sometimes with 



male or neutral ones intermixed. 

 B. Lemma and palea hyaline, the 

 glumes more or less indurated; 

 spikelets in 2's or 3's on the usu- 

 ally articulate axis of a spike-like 

 raceme, 1 sessile and perfect, usu- 

 ally awned, the other pediceled 

 and perfect, staminate or rudi- 

 mentary ........................ 



BB. Lemma and palea more or less in- 

 durated, firmer in texture than the 

 glumes; spikelets all perfect; first 

 glume sometimes obsolete ........ 3. MILLET TRIBE, OR 



1. INDIAN CORN 



TRIE: . 

 MAYDE.G. 



[TRIBE, OR 



J 



2. SORGHTJMTRIBE.OR 

 ANDROPOGONE.E. 



Subfamily II. POACOIDEJE. 



Spikelets 1- to many-fld., the imperfect or rudimentary floret, 

 if any, usually uppermost; rachilla usually articulated above the 

 glumes which arc persistent on the pedicel or rachis after the fall 

 of the florets; when 2- to many-fld., a manifest internode of the 

 rachilla separating the florets, and articulated below them; 

 spikelets more or less laterally compressed. 



A. Culms not woody and perennial. 

 B. Infl. paniculate, the spikelets pedi- 

 celed, not sessile on opposite sides 

 of a jointed flattened axis, form- 

 ing spikes, nor sessile along one side 

 of a slender continuous axis. 

 c, Spikelets 1-fld., the rachilla some- 

 times continued as a minute 

 bristle behind the palea (or in 

 Phalarideie a pair of rudimen- 

 tary or male florets below the 

 perfect one). 

 D. Spikclets falling entire; glumea 



usually obsolete or nearly so. . . 4. RICE TRIBE, OR 

 DD. Spikelets persistent ; glumes (ORYZE.E. 



present. 



B. Floret with 2 minute scales 

 (rudimentary lemmas) or 

 2 small male florets at- 

 tached at the base and fall- 

 ing with it ............... 5. CANARY-GRASS 



EE. Floret with no scales attached (TRIBE, OR 



below; glumes usually sub- [PHALARIDE^J, 



equal ; lemma awned or 

 awnless .................. 6. RED-TOP TRIBE, OR 



CC. Spikelets 2- to many-fld. (AGROSTIDE*. 



D. Glumes longer than the first 



floret; spikelets 2- to several- 



fld.; 1 or more of the florets 



usually awned from the bark 



or from between the teeth of a [A\ KNE,. 



bifid apex .................. 7. OAT TRIBE, OR 



DD. Glumes shorter than the first 

 floret; spikelets 2- to many- 

 fld ; awns when present ter- 

 minal or nearly so 8. FESOTTB TRIBE, OR 



BB. Infl. spieate. [FESTDCBJI. 



c. Spikelets sessile or subsessile in 

 1-sided spikes, 1- to few-fld. ; 

 spikes solitary, or digitately or 



racemosely arranged 9. CHLORIB TRIBE, OR 



CC. Spikelets sessile on opposite sides (CHLOHIDE.E 



of a zigzag jointed channeled 

 axis forming a spike; 1- ' to 



several-fld 10. BARLEY TRIBE. OR 



AA. Culms woody, tree-like : If .-blades [HORDE m. 



articulated with the sheaths 11. BAMBOO TRIBE, OB 



[BAMBUSE^R. 



//. Key to the Tribes. 



1. Indian Corn Tribe, or Maydea. 



A* Male spikelets in a terminal panicle; female 

 spikelets in spikes or ears in the axils of the 

 Ivs. 

 B. Female spikelets sunken in cavities of a 



jointed readily disarticulating axis 1, Euchlxna. 



BB. Female spikelets crowded in rows on a 



thickened continuous axis (the cob) 2. Zea. 



AA. Male and female spikelets in the same infl., 



the male at the end of the spikes. 

 B. Spikes digitate, the axis of the female por- 

 tion bony indurated, disarticulating with 



spikelets attached 3. Tripsacum. 



BB. Spikes paniculate, the female spikelets 

 inclosed in ovoid pearly or grayish bead- 

 like bodies, the male portion protruding 

 from a small orifice of the bead 4. Coix. 



2. Sorghum Tribe, or Andropogoneae. 



A. Spikelets all alike, perfect. 



B. Axis of racemes continuous, the spikeleta 



deciduous; panicle fan-shaped 5. Miscantkus. 



BB. Axis of racemes jointed, readily disarticula- 

 ting with the spikelets attached. 



c. The spikelets awnless 6. Saccharum. 



cc. The spikelets awned 7. Erianthut. 



AA. Spikelets not all alike, the sessile perfect, the 



pediceled male or neuter. 



B. Lower 1 or 2 pairs of spikelets unlike the 

 upper pairs; racemes in pairs from boat- 

 shaped sheaths on the ultimate branches 



of an elongated infl 8. Cymbopogon. 



BB. Lower pairs of spikelets like the upper, 

 c. Infl. consisting of 1 to many racemes, 

 these digitate or racemose along a 



short axis 9. Andropogon. 



cc. Infl. compound, paniculate. 



D. Racemes many-fld., linear, naked at 

 base, numerous, arranged in whorls 



on an elongated axis 10. Vetiveria, 



DD. Racemes reduced to 2 or 3 spikelets, 



arranged in a compound panicle 11. Holcus. 



3. Millet Tribe, or Panicete. 



A, Axis broad and corky, the spikelets sunken in 



its cavities 12. Steno- 



AA. Axis not broad and corky, spikelets not sunken [taphrum. 



in its cavities. 

 B. Spikelets not subtended or surrounded by 



bristles. 



C. Glumes and lemmas awnless, the apex of 

 the palea inclosed in the enfolding 



lemma 13. Panicum. 



CC. Glumes or lemmas, or both, awned or 



awn-tipped. 



D. Second glume and sterile lemma taper- 

 ing into an awn or point, coarsely 

 hispid; palea free at the summit; 



spikelets crowded 14. Echinochtoa. 



DD. Second glume and sterile lemma awned 



from a 2-lobed apex. 

 E. Infl. of 1-sided racemes along a com- 

 mon axis; spikelets pubescent but 

 not silky; palea inclosed at summit. 15. Oplismtnus. 

 EE. Infl. paniculate; spikelets covered 



with long silky hairs 16. Tricholxna, 



BB. Spikelets subtended or surrounded by 



bristles. 

 c. Bristles persistent, not falling with the 



spikelets at maturity 17. Setaria. 



CC. Bristles falling attached to the spikelet.. . .18. I'ennisetum. 



4. Rice Tribe, or Oryzeae. 



A. Spikelets unisexual, the female awned, erect 

 at the summit of the panicle, the male awn- 

 less, nodding on the lower branches 19. Zisania. 



AA. Spikelets perfect, strongly flattened 20. Oryza. 



