SYNOPSIS OF THE GENERA. 



simple nearly equal valves, mostly united at the base. 

 GhmcUa of one valve, with an awn arising from the base. 



16. Phal'auis, [Page 78.] Panicle contracted, or spreading. 



Glumes two, equal, keeled, longer than the G lamella. 

 Gliimelles of two equal awnless valves, at length forming 

 an indurated covering to the seed, and accompanied at its 

 base with one or two unequal imperfect florets. 



17. Ammo'phila, [Page 80.] Panicle spiked. Glumes nearly 



equal, keeled. Glumelles shorter than the glumes, hairy 

 at the base, the ow/er valve awned beneath the bifid apex. 



18., Gastridium, [Page 81.] Panicle contracted, spiked. 

 Glumes two, unequal, awnless, unequally swelled at tbe 

 base, much longer than the glumelles, which form a cover- 

 iiig to the seed; the outer valve mostly with a dorsal awn. 



19. MiL-iuM, [Page 81.] Panicle ^nead'wg. G/w/n^s two, equal, 



llallish, awnless, ribbed. Glumelles two, equal, shorter 

 than the glumes, smooth, shining, ribles.s, without awns, 

 forming a hard, permanent covering to the seed. 



20. Phlk'-um, [Page 82.] Panicle spiked, compact. Ghtmes 



nearly equal, acuminate, or the keel terminating in an awn; 

 Glumelles two, smaller, awnless, membranous. Seed ob- 

 long, loose. 



21. Lagu'kus, [Page 86.] PaM/c/e spiked, ovate. Glutnes oi two 



equal fringed valves, terminating in feathery awns. Glu- 

 mella of two unequal valves, external one the largest, 

 with a dorsal awn, bifid at the apex ; the lobes, long, rough, 

 awn-like. 



22. Sli'PA, [Page 87.] Panicle erect, or branched. Glumes of 



two nearly equal valves, longer than the glumella. Glumella 

 of two involute valves, the external one bearing from its 

 apex a long twisted awn, jointed at the base, and finally 

 separating at the joint. 



23. Polypo'gon, [Page 87.] Pa«ic/econtracted, somewhat spiked. 



Glumes of two equal awned valves. Glumella of two un- 

 equal valves, smaller than the glumes, the outer largest, 

 obtuse, awned at the extiemity. 



24. Cala'magrostis, [Page 89.] Panicle loose. Glumes two, 



longer than the glumella. Glumella of two unequal valves, 

 surrounded with hairs at the base, the outer valve awned 

 beneath the bifid apex? 



