402 MONOCOTYLEDONOUS PLANTS. 



24. ANTHOXANTHUM. Linn. 



Glumes 2-valved, 3-flowered. Lateral florets imperfect, 

 with one palea bearded ; intermediate florets perfect, much 

 shorter than the lateral ones. Palea obtuse, beardless. Sta- 

 mens 2. Seed free. Panicle contracted. 



Diandria. Digynia. 



A. odoratum Linn. : spike ovate-oblong ; flowers pubescent, subpe- 

 duncled, shorter than their awns. 



HAB. Moist meadows. N. Y. to Car. June Aug. 14- Culm 

 a foot high, assurgent. Flowers in a terminal spike or spiked 

 panicle. Introduced. Sweet-scented Vernal Grass. 



25. AIRA. Linn. 



Glumes 2- rarely 3-flowered, beardless, 2-valved, equal to 

 the florets or shorter ; one of the florets peduncled. Palea 

 2, equal, enclosing the seed when ripe; outer one usually 

 awned. Panicle compound. Triandria. Digynia. 



1. A. flexuosa Linn. : panicle spreading, trichotomous ; branches 

 flexuous ; glumes a little shorter than the pale and about the length 

 of the awn ; leaves setaceous ; culm nearly naked. 



HAB. Shady woods. Can. to Car. W. to Mich. June. !(. 

 Culm 1 2 feet high. Panicle capillary, lax, the branches whorl- 

 ed or dichotomous. 



2. A. ccspitosa Linn. : panicle diffuse ; palese about the length of the 

 glumes ; awn short, straight ; leaves flat. 



HAB. Swamps. Can. and N. S. July. it. Culms cespitose, 

 18 inches high. Panicle capillary, with the branches somewhat 

 whorled. 



3. A. aristulata Torr. : panicle capillary, spreading ; branches verti- 

 cillate and flexuous ; glumes 2-flowered, shorter than the paleee ; up- 

 per floret pedicellate ; lower palete truncate, laciniate, with an awn a 

 little below the middle scarcely exserted. 



HAB. Shores of lakes. N. Y. Aug. If. Culm 2 feet high. 

 Panicle oblong or pyramidal. 



4. A. pumila Pursh : panicle small, fastigiate, few-flowered ; pedi- 

 cels short ; paleee awnless, obtuse, twice the length of the glumes, 

 with membranous margins ; leaves flat, smooth ; culm erect, scarcely 

 longer than the leaves. 



HAB. Clay grounds. Penn. Pursh. June. l. Culms scarcely 

 an inch high, growing in tufts. 



26. AVENA. Linn. 



Glumes membranous, 2 7-flowered, longer than the flo- 

 rets. Lower palea bilaciniate, or with the upper bifid-toothed, 



