288 CONTRIBUTIONS FROM THE NATIONAL, HERBARIUM. 



19. MELICA L. 



Rather tall perennials with simple culms, narrow flat blades, and open or narrow 

 panicles; spikelets relatively large, the glumes thin, the lemmas firm, with strong 

 nerves. 



Lemmas awned from a 2-toothed apex; panicle branches long and divergent; culms 



not thickened at base 4. M. smithii. 



Lemmas awnless; panicle branches ascending; culms with a cormlike base. 



Spikelets narrow; lemmas acuminate 3. M. subiilata. 



Spikelets broad; lemmas obtuse or abruptly acute. 



Pedicels capillary, flexuous 1. M. spectabilis. 



Pedicels stouter, appressed 2. M. bella. 



1. Melica spectabilis Scribn. Onion grass. At middle altitudes, in meadows 

 or thin woods. B. C. to Oreg., Colo., and Mont. — Culms tall and slender, from an 

 onion-shaped base; panicle nodding, the beautiful bronze-purple spikelets about 12 

 mm. long. 



2. Melica bella Piper. West slope, in meadows at middle altitudes. Wash, and 

 Oreg. to Colo, and Alta. — Plants resembling the preceding, but not so tall, the culm 

 bases less thickened, the panicles stiffer, and the spikelets somewhat smaller. 



3. Melica subulata (Griseb.) Scribn. At low altitudes, in thin woods or on open 

 slopes. Alaska to Calif, and Mont. — Culms commonly 1 meter tall, the base a little 

 thickened; panicles elongate, the stiff branches ascending, the pale spikelets on 

 short erect pedicels. 



4. Melica smithii (Porter) Yasey. At low and middle altitudes, in woods. Wash, 

 and Oreg. to Wyo. and Mich. — A tall slender woodland grass with lax blades and 

 few-flowered, very open, nodding panicles. 



20. DISTICHLIS Raf. 



1. Distichlis spicata (L.) Greene. Saltgrass. East entri^nce, frequent in alkali 

 spots about dried-up pools on prairie. Widely distributed in N. Amer. — A low, 

 rather pale, sod-forming perennial, with numerous stiff spreading blades and narrow 

 compact panicles of smooth spikelets, the pistillate shorter and broader than the 

 staminate. 



21. POA L. Bluegrass. 



Slender grasses with simple, mostly erect culms, narrow blades ^nth boat-shaped 

 tips, and open or compact panicles of relatively small spikelets. 



Plants annual, low 1. P. annua. 



Plants perennial. 

 Plants producing rootstocks and forming a sod. 



Culms conspicuously flattened, wiry; panicle rather narrow and compact. 



2. P. compressa. 

 Culms terete or nearly so; panicle open. 

 Spikelets mostly less than 6 mm. long; lemmas pubescent on the nerves and 



with a cottony tuft at base 3. P. pratensis. 



Spikelets mostly 8 to 10 mm. long; lemmas glabrous on the nerv^es and not 



cottony at base 4. P. wheeleri. 



Plants not producing rootstocks; bunchgrasses. 

 Lemmas pubescent on the nerves and sometimes cottony at base. 



Lemmas cottony at base (with a few long fine crinkly hairs) distinct from the 

 pubescence of the nerves. 



