GRAMINEAE (GRASS FAMILYJ 65 



cylindrical, enveloping the palet; long internode of the rachilla 5-nerved, the 

 three prominent nerves terminating in 3 long straight twisted awns. 



1. Scleropogon Karwinskianus (Fourn.) Benth. Wats. Proc. Am. Acad. 

 18: 181. 1883. Culms 1-3 dm. high, generally simple above the caespitose 

 leafy base: staminate spikelets 5-8, 1-3 cm. long; pistillate spikelets 1-2 cm. 

 long; awns rigid, several times longer than the florets. Colorado to Texas and 

 Arizona. 



43. MUNROA Torr. 



A low tufted grass, with flat rather thick leaves fasciculately crowded at 

 the nodes. Spikelets 3-5-flowered, perfect or the upper florets sterile, sessile 

 in leafy clusters at the nodes and ends of branches. Glumes thin, lanceolate, 

 subequal, slightly shorter than the contiguous florets; lemmas herbaceous or 

 coriaceous, obtuse or dentate, mucronate, convex, enveloping the palet and 

 stamens. Grain translucent, broadly spindle-shaped. 



1. Munroa squarrosa (Xutt.) Torr. Pac. R. R. Rep. 4: 158. 1856. Culms 

 1-2 dm. high, spreading, fasciculately branched : leaves 2-3 cm. long, rigid 

 and pungent: spikelets 2-5-flowered, the flowers perfect: glumes shorter than 

 the 3-toothed lemma; palet obtuse. From Montana to Texas and Arizona. 



44. PHRAGMITES Trin. REED GRASS 



Tall stout broad-leaved grasses from long perennial rootstocks. Spikelets 

 3-7-flowered, cuneate, in large plume-like panicles. Glumes lanceolate, the 

 second one a third longer than the first and about equaling the florets; lemma 

 lanceolate, attenuate, entire, glabrous, much longer than the palet; inter- 

 nodes of rachilla pilose with silky hairs as long as the florets. 



1. Phragmites communis Trin. Fund. Agrost. 134. 1820. Culms 2-3 m. 

 high: leaves narrowed at the base: spikelets nearly 1 cm. long. Wet land 

 throughout the United States; often improperly called Pampas (Irass. 



45. TRICUSPIS Beauv. 



Tufted perennial grasses with short pointed strongly keeled leaves and 

 simple or compound panicles. Spikelets (in ours) compressed, in short sub- 

 capitate panicles on the simple nearly naked culms, bleaching white at ma- 

 turity. Stamens 3. Styles short, with plumose stigmas. Grain free, inclosed 

 in the lemma. Triodia in part. 



1. Tricuspis acuminata Munro, Gray Proc. Acad. Phila. 1863: 335. Stems 

 simple, 1 dm. or more high, usually with but a single node, which bears a very 

 short leaf: radical leaves 3-5 cm. long; those of the stem shorter: panicle 

 dense, ovoid, 3-4 cm. long, with a few erect branches: spikelets 8-12-flowered: 

 glumes acuminate, the upper subaristate; lemma scarcely bifid, with a central 

 seta one fourth its length, densely silky below, with a conspicuously silky tuft 

 near the base. Triodia acuminata. Colorado and Utah to Texas and Arizona. 



46. REDFIELDIA Vasey 



A tall perennial grass with long narrow leaves and an ample panicle. Spike- 

 lets 1-3-flowered, the flowers perfect. Glumes about equal, 1-nerved; lemmas 

 membranous, 5-nerved, with a ring of hairs at the base; palet 2-nerved, shorter 

 than the lemma. Stamens 3. Styles long, distinct; stigmas short, plumose. 

 Grain free, oblong. Graphephorum in part. 



1. Redfieldia flexuosa (Thurb.) Vasey, Bull. Torr. Bot. Club 14: 133. 1887. 

 Stems 5-7 dm. high, smooth: leaves 3-5 dm. long, setaceous-acuminate: 

 panicle loosely flowered; branches scattered: spikelets ovate, 3-6-flowered, 



ROCKY MT. BOT. 5 



