SYNOPSIS OF THE GENERA. 



simple nearly equal valves, mostly united at the base. 

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



16. PHAL'ARIS, [Page 78.] Panicle contracted, or spreading. 



Glumes two, equal, keeled, longer than the Glumella. 

 Glumelles of two equal awnless valves, at length forming 

 nn 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 outfr valve awned beneath the bifid apex. 



1&. GASTRIDIUM, [Page 81.] Panicle contracted, spiked. 

 Glumes two, unequal, awnless, unequally swelled at the 

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

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



f9. MIL'UIM, [Page 81.] Panicle spreading. Glumes two, equal, 

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

 than the glumes, smooth, shining, ribless, without awns, 

 forming a hard, permanent covering to the seed. 



20. PBLK'UM, [Page 82.] Panicle spiked, compact. Ghemes 



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

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

 long, loose. 



21. LAGU'RUS, [Page 86.] Panicle spiked, ovate. Glumes of 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. STI'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.] Panicfecontracted, 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 extremity. 



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. 



