GRASS FAMILY 



137 



7. Oryzopsis bloomeri (Boland.) Ricker. 

 Bloomer's Aluuntain-rice. Fio-. 297. 



Stipa btoomeii Boland. Proc. Calif. Acad. 4: 168. 1872. 



Oryzopsis bloomeri Ricker; Piper, Contr. U. S. Nat. Herb. 11: 

 "109. 1906. 



Culms tutted, 30-60 cm. tall, glabrous ; sheaths gla- 

 brous ; ligule about 1 mm. long; blades crowded at the 

 base, involute, narrow, firm; panicle 7-15 cm. long, the 

 branches slender, rather stiffly ascending, the longer 

 5-7 cm. long, bearing spikelets from about the middle ; 

 glumes comparatively broad, indistinctly 3-5-nerved, 

 smooth, rather abruptly acuminate, equal, 8-10 mm. 

 long ; lemma elliptic, 5 mm. long, densely long-villous ; 

 awn about 12 mm. long, tardily deciduous, once-genicu- 

 late, the first section about 6 mm. long, slightly twisted, 

 appressed-villous, indistinctly bent or flexuous, the second 

 section straight, minutely scabrous. 



Dry ground, Arid Transition Zone; eastern Washington to 

 California (Moulton, Mount Diablo, Lancaster), east to Manitoba 

 and New Mexico. June-July. Type locality: near Mono Lake, 

 California. 



19. MUHLENBERGIA Gmel. Syst. Nat. 2: 171. 1791. 



Spikelets 1-flowered, the rachilla disarticulating above the glumes; glumes usually 

 shorter than the lemma, obtuse to acuminate or awned, the first sometimes small or rarely 

 obsolete ; lemma membranaceous, 3-5-nerved, with a very short usually minutely pilose 

 callus, the apex acute, sometimes bidentate, extending into a straight or flexuous awn, or 

 sometimes only mucronate. Perennial or rarely annual low or moderately tall grasses, 

 tufted or bearing rhizomes, the culms simple or much-branched, the inflorescence a narrow 

 or open panicle. [Named in honor of Rev. Dr. Henry Muhlenberg, a distinguished American 

 botanist, 1753-1815.] 



Sijecies about 80, mostly in Mexico and soutlnvestern L'nited States, a few in the eastern part of the 

 Old World. Type species, Mithleiibergia schrcbcri Gmel. 



Plants annual (see also no. 9); lemma bearing a capillary awn. 1. M. microspcrma. 



Plants perennial. 



Plants producing creeping scaly rhizomes. 



Hairs at base of floret copious, as long as body of lemma. 2. M. andina. 



Hairs at base of floret inconspicuous, not more than half as long as lemma. 



Blades short and narrow, usually less than 2 mm. wide, often involute; lemma awnless or mucronate. 



Culms erect or decumbent at base; glumes 1 mm. long. 3. M. squarrosa. 



Culms widely spreading or creeping; glumes 1.5 mm. long. 4. 71/. repens. 



Blades rather long, more than 2 mm. wide (except in M. Icmmoni), flat; lemma sometimes awned. 



Glumes awned, the awn much exceeding the awnless lemma; panicle compact, like an interrupted 

 spike. 5. M. racemosa. 



Glumes acuminate or short-awned, not much longer than the body of the lemma; panicles mostly 

 slender. 

 Sheaths scabrous; blades firm; plants branched from the base; awn 2-3 mm. long. 

 Blades about 2 mm. wide. 6. M. lemmoni. 



Blades 3-5 nun. wide. 7. M. californica. 



Sheaths glabrous; blades thin; plants branched above the base; awn more than 3 mm. long. 



8. M. foliosa ambigua. 



Plants without creeping scaly rhizomes. 

 Lemma mucronate or short-awned. 



Culms delicate, the base often appearing to be annual; blades mostly less than 2 cm. long; glumes 

 entire. 9. .1/. filiformis. 



Culms moderately stout, from a firm base; blades mostly more than 3 cm. long; second glume 

 truncate, toothed. 10. M. jonesii. 



Lemma distinctly awned. 



Panicles diffuse; plants widelv spreading, much-branched, fragile, wirv, the base knotty. 



11. M. porteri. 



Panicles narrow; plants cespitose, erect from a short decumbent base. 12. .1^. montaim. 



