400 MONOCOTYLEDONOUS PLANTS. 



Div. III. STIPACEJE. Inflorescence paniclcd. Spikclete 

 solitary, \~flowered. Glumes membranous, the lower palea; 

 coriaceous, bearded, enfolding the upper, which has not two 

 keels. 



20. STIPA. Linn, 



Glume 2-valved t membranous. Palea 2, coriaceous, short- 

 er than the glume ; the lower involute, with a long beard ut 

 the apex ; upper entire. Awn jointed at the base, deciduous. 

 Seed furrowed. Panicle almost simple, lax. 



Triandria. Digynia. 



S. (menaced Linn. : leaves setaceous ; panicle spreading, somewhat 

 eecund ; branches mostly in pairs, a little divided ; glume as long a 

 the seed ; awn naked. & barbala Mich. 



HAB. Sandy soils. N. Y. to Car. June. !(. Culm 2 feet high. 

 Panicle 46 inches long, becoming diffuse. Feather Grass, 



Div. IV. BROMF..K. Inflorescence panided. Spikelets soli- 

 tary, 2 or many-flowered. Glumes with a keel. Palea of 

 nearly the same texture as the glumes, the lower carinate or 

 concave, always bearded, the upper with two keels. 



21. ARISTIDA. Linn. 



Glume 2-valved, membranous, unequal. Palea 2, pedicel- 

 late, subcylindric ; lower one coriaceous, involute, 3-awned 

 at the tip ; upper one very minute or obsolete. Scales collat- 

 eral. Panicles contracted. Triandria. Digynia. 



1. A. dichotoma Mich. : cespitose ; culm dichotomous ; flowers ra- 

 cemose-spiked ; lateral awns very short, the intermediate one con- 

 torted. 



HAB. Gravelly soil. N. Y. to Car. July. . ? Culms 1213 

 inches high, very slender. Racemes on clavate peduncles. 



2. A. stricta Mich. : culm and leaves straight, erect ; leaves pubes- 

 cent ; raceme long, somewhat spiked, crowded ; awns twice as long 

 as the paleee, spreading. 



HAB. Rocky places. Penn. to Car. July. U.Culm 23 

 feet high, branching at base. Panicle long, with the flowers not 

 crowded. 



3. A. purpurascens Poir. : culm filiform, erect, simple ; leaves very 

 narrow, flat ; flowers in a long spiked panicle ; awns nearly equal, 

 twice the length of the pale, divaricate. A. racemosa Muhl. 



HAB. Sandy woods. N. S. Sept. U- Culm 2 a feet high- 

 Panicle elongated, loose. 



22. CALAMAGROSTIS. Rotk. 

 Glume 2-valved, 1-flowered ; valves acute or acuminate. 





