158 PATAGONIAN EXPEDITIONS I BOTANY. 



2.. Floral glume usually exceeding the empty glumes ; not awned or awned only 



from the point and the awn not bent. (FESTUCE/E.) 

 /. Floriglume surrounded by long hairs. Lower flower male or abortive. Tall 



aquatic. 39. Phragmites, p. 212. 



/2. Floriglume dividing into awn-like parts. Panicle spike-like. 



38. Pappophorum, p. 211. 



/3. Spikelets unisexual. Creeping with minute, distichously crowded leaves. 



40. Monanthochloe , p. 212. 



/4. Axis of spikelet or floral glume with long hairs (at least in the fertile 



flowers). Tall, tubular grasses. 41. Gynerium= Cortaderia, p. 213. 



/5. Axis and floral glumes naked or with only short hairs. Stigmas feathery. 



Spikelets all alike. 



g. Floral glume 2-3 -toothed, usually 3-nerved ; lateral nerve and callus 



usually hairy. Spikelets with 3-several fertile flowers and 2 empty 



glumes. 42. Sieglingia= Triodia, p. 214. 



g2. Floral glumes 1-3 -nerved, all with perfect flowers or the uppermost 



male or empty. 

 h. Branches or panicles spirally arranged. 



i. These branches being spike-formed racemes with subsessile spike- 

 lets. Floral glumes carinate. 43. Diplachne, p. 214. 

 12. The branches again branching, shorter upwards. Spikelets 

 dense, many-flowered, with a strong axis. 



44. Eragrostis, p. 215. 

 h2. Primary branches of panicle distichously arranged (branching 



further at base). 

 i. Panicle spike-like. Empty glumes not broader nor longer than 



the floral glumes. 45. Koeleria, p. 216. 



12. Panicle expanded with soft, long branches. Empty glumes 



slightly unequal. 46. Catabrosa, p. 216. 



3. Floral glume 3-5-many-nerved, all with perfect flowers, or the upper- 

 most male or empty, appressed or embracing. Empty glumes 

 mostly clavate, not awned ; floral glumes sometimes awned. 



47. Melica, p. 217. 



g4. Floral glumes 5-many-nerved, all or all but the uppermost jvith per- 

 fect flowers, often several empty glumes at top. Leaves without 

 distinct cross-veins. 



h. Plant dioecious. Spikelets sessile. 48. Distichlis, p. 217. 



h.2. Plant hermaphrodite (very rarely dioecious, and then laxly -panic- 

 ulate). 

 i. Floral-glumes cordately lobed at the base. 



49. Briza, p. 218. 

 12. Floral glumes not basi-cordate. 



j. Spikelets panicled or racemed, imbricating or glomerulate. 

 Panicle-branches 1-5. 



k. Stigmas 2, apical. Floral glumes, at least of the upper 

 flowers, protruding above the empty glumes. 



