TRIANDRIA, DIGYNIA. 51 



47. Pznnisetum, Richard. 



Inoolucrum composed of man}' seta; (or bris- 

 tles.) Calix 2-valved, valves unequal, 2- 

 flowered ; one of the flowers hermaphrodite, 

 the other masculine (or rarely neuter) both 

 sessile. (Flowers spiked, polygamous.) 



jyif/t. 



1. P. spike cylindrical: involucels two-flowered, giaucum. 



hairv, fasciculate ; seeds crossed by undulate 



wrinkles. Sp. pi. 

 Panicum giaucum, JVilld. 



Very common, flowering all summer. Annual. 



3, P. spike terete sub-compound, undivided, invo- ririi* 



lucels bristly small, seed nerved. Willd, 

 Panicum viricle, Willd. 



Not common, and seems to be introduced. Annual. July. 



3. P. spike verticillate, the little racemes in fours, ▼wtkUk- 

 involucels one-flowered two-bristled, culm diffuse. IU1U * 

 Willd. 



Panicum verticillatum, Willd. 



This species also seems to be introduced, common. Mr. 

 Elliot has piven Panicum alopicuroideum, of Walt., as a sy- 



ivm to No. 1-, and Pursh adds it to the present species, 

 saying, he has seen it in the herbarium of Walter. Annual. 



48. Dicitaria, Haller, Richard. 



Calix 2 or 3-valved, concave ; exterior valve 

 minute, or none, second variable, the inner- 

 most as long the corolla. Corolla 2-valved, 

 oblong- ovate, terete, and awn less. Style 

 very long. Nectary cleft. jYutt. 



1. D- spikes expanding ; spikelets 2-flowered ; one »anguuiaiii. 

 sessile ; stem decumbent, creeping. 



