3l8 SYSTEMATIC BOTANY. 



6. Aristida. Spikelets i-flowered. Glumes 2, unequal, often 

 mucronate ; paleae pedicellate ; lower tipped with 3 awns ; upper palea 

 much smaller, minute. Stamens 3. Stigmas plumose. 



A. DICHOTOMA (Poverty Grass). Culms tufted, dichotomously and very 

 branching ; leaves very narrow, more or less revolute ; spikelets on clavate 

 pedicels, in short, appressed racemes ; lateral ones minute, middle one as 

 long as or longer than the palea, bent or twisted. In sandy fields, 6'-i2' high. 

 August-September. 



7. Dactylis. Spikelets 2 -3-flowered, aggregated in dense clusters, 

 forming a dense, branching, i-sided panicle. Glumes unequal, cari- 

 nate, mucronate. Stamens 3. y. 



D. GLOMERATA (Orchard Grass). Culm erect, somewhat rough ; leaves 

 linear-lanceolate, rough, somewhat glaucous ; panicle dense, with remote 

 branches ; glumes very unequal ; anthers large, yellow. In shaded fields, 

 especially orchards. 2-3 feet high. June. 



8. Poa. Spikelets compressed, ovate or oblong, few-flowered, in 

 loose, open panicles. Glumes usually shorter than the flowers ; the 

 lower one smaller. Lower palea 5-nerved, with a soft, web-like down. 

 Upper palea smaller, 2-toothed, deciduous with the rest of the flower. 

 Stamens 2-3. 



1. P. ANNUA (Low Meadow Grass). Culms low, mostly decumbent or 

 spreading, somewhat compressed ; leaves short, smooth, with smooth sheaths ; 

 panicle nearly as long as broad, with mostly solitary, at length horizontal 

 branches ; spikelets 3-6-flowered, on very short pedicels, much crowded ; 

 flowers slightly downy near the apex. Common everywhere, 3'-6' high. 

 May-November. 



2. P. PRATENSIS (Meadow Grass). Culm erect, round, smooth ; leaves 

 with smooth sheaths ; ligules short, truncate ; panicle pyramidal, diffuse ; 

 branches spreading, in half- whorls of 4-5 ; spikelets 3-5-flowered, nearly ses- 

 sile, densely crowded on the branches. May-July. 



9. Festuca. Spikelets 3-io-flowered, in open or racemose pani- 

 cles. Flowers not webbed at base. Glumes unequal. Paleae rounded 

 on the back, entire, acute, and often awned at apex. Upper palea usu- 

 ally adhering to the ripe caryopsis. Stamens mostly 3. 



1. F. TENELLA (Slender Fescue Grass}. Culm very slender, wiry, 

 mostly simple ; leaves very narrow ; panicle simple, with racemose branches, 

 contracted so as to resemble a spike ; spikelets 6-8-flowered ; palea tipped 

 with an awn shorter than itself. In dry soils, 6'-i2' high. June-July. 



2. F. ELATIOR (Tall Fescue Grass). Culm smooth, erect ; leaves broad- 

 linear ; panicle open, loosely branching, with spreading, drooping branches ; 

 spikelets crowded, 4-6-flowered ; lower palea awnless. In meadows, 2-4 

 feet high. June. 



