2. E. ciliaris, H. B. K. Texas to Arizona. 



3. E. Nuttallii, Vasey. (Andropogon, Chap.) Florida to Texas. 



Dr. V. Havard states that this species forms a large portion of 

 the vegetation of the plains of Southeast Texas. 



Rottbcelia, Linn. 



Flowers in terminal and lateral cylindrical spikes. Spikelets in 

 pairs at each joint of the rhachis, one sessile and imbedded in an 

 excavation of the rhachis, the other short pedicelled, erect and ap- 

 pressed. The sessile spikelet has two thick outer glumes, two hya- 

 line ones and a hyaline palet, with the stamens and pistil. Rarely 

 this spikelet has a second male or imperfect flower. The pedicelled 

 spikelet is usually imperfect, male only or reduced to empty glumes. 



1. R. corrngata, Bald. South Carolina to Texas. 



2. R. cylindrica, Chap. Florida to Texas. 



3. R. rugosa, Nutt. Delaware to Florida. 



Manisubis, Swartz. 



Spikelets in pairs in the one-sided notches of the articulate rhachis 

 of a simple spike, one sessile and half imbedded in a cavity of the 

 rhachis, with one perfect flower, the other on a short appressed 

 pedicel and reduced to two empty glumes. Outer glumes of per- 

 fect flower two, the lower globular and hard, the second smaller 

 and concave, thin but rigid. Third and fourth glumes small and 

 hyaline. Palet, none ; the fourth glume usually considered a palet. 

 1. M. granulans, Sws. Introduced. Texas and New Mexico. 



Hemakthkia, R. Br. 



Spikelets in pairs in the alternate notches of a simple spike, one 

 sessile and half imbedded in a cavity of the scarcely articulate rha- 

 chis, with one perfect flower, the other on a closely appressed and 

 often adnate pedicel reduced to 2 or 3 empty glumes ; the spikes 

 terminal and lateral, and with the culm often flattened. Glumes in 

 the sessile spikelet 4, the outer one thick, appressed and covering 

 the cavity of the rhachis, the second thinner and convex or keeled, 

 the third and fourth and the palet in the fourth thin and hyaline. 



1 . H. f asciculata, Kth. Southeast Texas. 



