38 TRIANDRIA. MONOdYNlA. 



tropics; one, the F. imibellata, is also common to India; the 

 4th species, F. ca7iescens, is a native of Africa. 



58. CENCHRUS. (Bur-grass.) 

 77iro^HcnnnIaciniate, echinate, 3 to 4-flower- 



ed. Calix 2-valved, 2-flowered, 1 fertile the 

 other sterile. Style bifid, (sometimes 2.) 



Culm round, in some species branched; flowers in- 

 spikes or racemes; proper involucrum caliciform, spiny or 

 hispid, sometimes roundish with a laciniate margin, in 

 other species setiform, or more or less deeply divided. 



Species. 1. C. echinahis. 2. tribnloides. 



Of this genus there is 1 species in India, but doubtful 

 as a Cenchnis, 3 in Barbary, besides the C. echinatus equal- 

 ly indigenous to the United States; the C. capitatus of 

 Barbary, exists also in France and Italy, and the C. hor- 

 deiforynis is found also in Asia. There is another species in 

 Babao, one of the Friendly islands; another in Montevideo 

 in South America; 2 others at tlie Cape of Good Hope; 

 and lastly, a shrubby species in the mountains of Ar- 

 menia. 



This genus is very nearly allied to Pennisetim. 



59. LIMNETIS. Richard. Trachynotia. M- 

 chaiix, Spartina. Schreber, (Marsh-grass.) 



Flowers in unilateral sjjikes almost imbri- 

 cated in 2 rows. — Calix 2-valved, carinate, and 

 con»pressed; one of the valves much smaller 

 than the other. Corolla 2-valved, awnless. Styles 

 long, 1 or 2, Perisporium 0. Seed com- 

 pressed. 



Culm round, I'arely hollow, often tall, {\\\e L. polysta- 

 chya from 3 to lO feet higli); leaves large and long; spikes 

 in a simple oppressed or expanding panicle, long, and 

 many-flowered; valves of the calix very unequal, the larger 

 valve acutely carinate; the carina almost aculeate or 

 sharply ciliate. Seed compressed, oblong. 



Notwithstandirg the great disparity of habit, this ge- 

 nus is very nearly allied to the DaciyUs,3it least to the D. 

 glomerate, which occurs sometimes 1-flowered. 



Species. 1. L. juncca. 2. cynosuroides. o.polystachya.A;. 

 glabra. This last species grows up the Missouri as far as 

 the great Northern Bend, around Fort Mandan. The ge- 

 nus Umnetis, with the exception of the L. pxtngens of 



