10-15 cm. long, pale, rather loose, the branches short-appressed; spikelets 3- to 

 5-flowered, 6-8 mm. long; glumes narrow, the second about as long as the lowest 

 floret; lemmas 4-5 mm. long, rather obtuse at the scarious tip. 



Low meadows and other such wet places, in Ariz. (Kearney & Peebles) ; Mont, 

 to Wash, and Yuk., s. to Colo., Ariz, and Calif. 



10. Poa juncifolia Scribn. 



Strongly tufted perennial sometimes producing rhizomes, 4-12 dm. tall; sheaths 

 smooth to scaberulous, rarely closed as much as one fourth their length; innova- 

 tions usually numerous, their blades often 1-3 cm. long, from involute and 

 almost filiform to flat and as much as 3 mm. wide; culm leaves usually shorter 

 than those of the innovations; ligules rather thick, truncate to rounded, strongly 

 scaberulous-puberulent and finely ciliolate, from 0.5 mm. long on the innovations 

 to as much as 2 or 3 mm. long on the upper culm leaves; panicle narrow, 

 usually 6-20 cm. long, the branches mostly erect; spikelets 3- to 7-flowered, (5-) 

 7-10 mm. long; glumes slightly unequal, usually 3-nerved, the first mostly 3.5-4.5 

 mm. long, the second 4—5 mm. long; lemmas slightly keeled, 4-6 mm. long, 

 without a basal web and usually either finely scaberulous over the back or glabrous 

 over the lower half, sometimes scabrous above and very finely crisp-puberulent 

 on the lower fourth; anthers 2-3 mm. long; lodicules about 0.7 mm. long. P. 

 ampla Merrill. 



In marshes, wet alkaline meadows and rocky open slopes, in N.M. [Hitchcock) 

 and Ariz. (Santa Cruz Co.); Alta., Neb., the Dakotas to B.C., s. to N.M. and 

 Calif. 



7. Briza L. Quaking Grass 



A genus of 20 species in temperate North America and South America; we 

 have only a single species. Another species, B. maxima L., the big quaking grass, 

 is occasionally cultivated but does not persist or escape. 



1. Briza minor L. Little quaking grass. Fig. 85. 



Annual; culms 1-4 dm. long, erect or at the very base shortly decumbent; 

 ligule a long hyaline scale sheath shorter than the internodes, having an inverted 

 V-shaped juncture to the blade; blades 5-10 mm. broad, flat; panicle broadly 

 ovoid, 5-12 cm. long, about as broad, open, diffuse, with ascending-spreading 

 branches that are twice trichotomous and naked; spikelets pendulous from the 

 ultimate capillary pedicels at the periphery of the panicle, 3-5 mm. long, 6- to 

 8-flowered, broader than long, markedly tapered, only very slightly laterally com- 

 pressed; glumes 2, very broad, spreading, 3-nerved, with broad hyaline margins; 

 lemmas 1.5-2 mm. long, spreading cymbiform, 5-nerved, marginally broadly 

 hyaline, basally auriculate and thus basally overlapping each other; rachilla 

 abscising above the glumes and at the lower part of each node. 



Infrequent in swales and in woods or open sandy soil, in marshes, wet meadows 

 and seepage areas, in e. and s.e. Tex., spring; nat. of Eur., widely introd. in 

 the U.S. 



8. Eragrostis Beauv. Lovegrass 



Variable in habit and foliage; panicles usually much-branched (the branches 

 in some species very short and closely appressed); spikelets usually somewhat 

 laterally compressed, several-flowered; glumes shorter than the lowest lemma, 

 1-nerved; lemmas 3-nerved (lateral nerves sometimes obscure); rachilla either 

 remaining intact (lemmas then deciduous) or abscising above the glumes and 

 either at the upper or lower part of each lemma-node or breaking irregularly 

 between the florets under mechanical pressure during tumbling of the panicle. 



192 



