tufted base; blades mostly less than 15 cm. long, 3-6 mm. wide; panicle 1-5 cm. 

 long or broadly cylindric; glumes 5 (sometimes 7) mm. long, oblong, hispid- 

 ciliate on the keel, the stoutish awns 2 mm. long to give the head a bristly 

 appearance. 



In wet mt. meadows, bogs, marshes and mud on edge of lakes and ponds, in 

 N. M. (Rio Arriba, San Juan, Santa Fe, San Miguel and Taos cos.) and Ariz. 

 (Apache and Coconino cos.); Greenl. to Alas., s. to N. H., Mich., N. M., Ariz, 

 and Calif.; Euras. 



32. Gastridium Beauv, 

 Two species in the Canaries, western Europe and the Mediterranean region. 

 1. Gastridium ventricosum (Gouan) Schinz & Thell. Nit grass. Fig. 116. 



Plants annual; culms 1-5 dm. tall; foliage scant, the blades flat, scabrous; 

 panicle 3-8 cm. long (or in robust specimens 10-14 cm. long), dense, shining, 

 spikelike; spikelets 1 -flowered, slender, about 5 mm. long; glumes long-acuminate, 

 somewhat swollen at the base, scabrous on the keels, the second glume about three- 

 fourths as long as the first; lemmas much shorter than the glumes, hyaline, 

 globular, pubescent, truncate, with a delicate, somewhat bent awn 5 mm. long; 

 palea about as long as the lemma. 



Established usually on open, dry ground, but occasionally found in marshy 

 sites along streams or around vernal pools, in Ariz. (Pima Co.); Ore. to Calif, 

 and Ariz.; introd. from Eur. 



33. Muhlenbergia Schreb. Muhly 



Perennial or rarely annual low or moderately tall or rarely robust grasses, 

 tufted or rhizomatous; culms simple or much-branched; inflorescence a narrow 

 sometimes spikelike or open panicle; spikelets 1 -flowered or occasionally 

 2-flowered, the rachilla disarticulating above the glumes; glumes usually shorter than 

 the lemma or sometimes as long, obtuse to acuminate or awned, keeled or convex 

 on the back, the first sometimes small or rarely obsolete; lemma firm-membranace- 

 ous, 3-nerved with the nerves sometimes obscure or rarely an obscure additional 

 pair, with a very short callus, rarely long-pilose, usually minutely pilose, the apex 

 acute, awned from the tip or just below it or from between very short lobes, some- 

 times only mucronate, the awn straight or flexuous. 



A genus of more than 100 species that occur from the Himalaya Mts. to Japan, 

 and from North America to the Andes. The genus, as now interpreted, is very 

 diverse, being a taxonomic dumping ground. Some of the muhlys are quite 

 abundant and are valuable forage. 



1. Annuals (doubtful cases should be keyed under both alternatives) (2) 



1. Perennials (4) 



2(1). Lemma with awn 1-3 cm. long 2. M. pectinata. 



2. Lemma awnless (3) 



3(2). Pedicels capillary, elongate; glumes minutely pilose 1. M. minutissima. 



3. Pedicels short, appressed; glumes glabrous 3. M. filiformis. 



4(1). Rhizomes developed, usually prominent, scaly, creeping, often branching 

 (5) 



4. Rhizomes wanting; culms tufted, usually erect (12) 



5(4). Blades 2 mm. wide or less, mostly short and involute (6) 



5. Blades flat, at least some of them more than 3 mm. wide, usually 5 mm. wide 



or more (8) 



243 



