20 GKAMINEAE 



Spikes sy or less long, V or less thick, not notice- 

 ably coinpouiid. 



Spikes j-ellow, very erect and closely flowered. 3. C. gUiuca. 



Spikes {jreen, less closely flowered and more 



nodding. 2. C. viridis. 



1. C. verticillata (L.) Scribn. Foxtail. 1°-2° high, with a pale 

 green spike ^'-'.V long : bristles one or two to each flower, slightly ex- 

 ceeding the spikelet. — Waste places in Independence. Uncommon. 



2. C. glauca (L. ) Scribn. Ykllow Foxtail. 1°-4° high, the 

 slightly flexnons tawny yellow spike V-i^ long : bristles 6-11 to each 

 spikelet, much longer than the spikelet : first scale shorter than the 

 second : third and fourth scales equal, longer than the second : fourth 

 scale transversely rugose. — Extremely abundant in waste places, corn- 

 fields, along railroads and the like. 



3. C. viridla (L. ) Scribn. Gkeex Foxtail. Closely resembles the 

 last, but the green spikes are more nodding and less closely flowered, 

 and the bristles are fewer in number : the first scale one-third the length 

 of the other three, which are about e(jual in length : fourth scale striate 

 lengthwise and pitted. — Growing with the last and about as common. 



4. C. Italica ( L. ) Scribn. Millet. 2°-5° high with a large com- 

 pound spike, 4^-8' long, lO^'-l.y^ broad, usually interrupted at base: 

 bristles 2-3 : spikelets much as in the last : heads nodding or erect. — 

 Occasionally escaped into waste lots and along railroads. 



Var. Germanica (Mill.) Scribn. HuxoAElAN GRASS. Smaller than 

 the species : spikes about 6'^ broad : bristles usually purplish. — In simi- 

 lar situations as the type. 



10. CENCHRUS L. 



Spikelets awnle.ss ; as in I'anicum, but several arc enclosed together in a 

 horridly spin}- involucre. Involucres forming an interrupted terminal 

 spike. 



1. C. tribuloides L. P.rE-ORASS. A decumbent annual, 8'- 20' high : 

 spikes about 2' long, with 8-20 two-flowered heads: involucres pubes- 

 cent, covered all over with short stout barbed spines. — A troublesome 

 weed, often common in sandy grounds along the Missouri River. July- 

 October. 



11. ZIZANIA L. 



A tall acjuatic with monoecious flowers in a terminal panicle. Upper 

 flowers pistillate and erect, long-awned, the lower staminate and droop- 

 ing, unawned. Glumes two. Stamens six. 



1. Z. aquatica L. Wild Rice. Annual, 3°- 10° high, with long flat 

 leaves, l°-3° long : spikelets very deciduous, and early breaking from 

 the rachis. — In the lake at Lake City. Rare. July-October. 



12. HOMALOCENCHRUS Mieg. Cut-gkass. 

 Lowland grasses with flat spikelets crowded in one sided panicles. 

 Spikelets usually imbricated over each other. Glumes two, strongly 



