ORDEE 156. GRAMINEJ3. 779 



nate, stigmas pluinous, 'elongated. Panicle contracted into a. cylindric, 

 dense spike. 



1 A. pratensis L. Culm erect, smooth, leafy, about 2f high, bearing an erect, 

 dense, many-flowered, cylindric, obtuse, compound spike, about 2' long; Ivs. 

 flat, smooth, the upper shorter than its swelling sheath ; stipules ovate ; glumes 

 ciliate, connate below the middle, as long as the pale; awn twisted, scabrmts, 

 nearly thrice the length of the flower. U Fields and pastures, Northern States. 

 An excellent grass. Jn., Jl. . 



2 A. geniculatus L. BENT FOX-TAIL. Culm ascending, geniculate below, spar- 

 ingly branched, 1 fif high; spike cylindrical, about 2' long; Ivs. linear, 3 6' 

 long, the upper equaling or exceeding the smooth, flat, acute, slightly inflated 

 sheath ; stipules oblong, entire ; glumes slightly connate at base, hairy outside ; 

 palecB truncate, smooth, half as long as the gtniculate awn. 1{ Wet meadows, N. 

 Eng., Mid. States and Brit. Am. Jn. 



3 A. aristulatus MX. WILD WATER FOX-TAIL. Glaucous; culm decumbent 

 at base, bent at the joints, ascending 1 to 2f; Ivs. linear, flat, gradually acute ; 

 glumes subequal, pubescent, obtuse, shorter than the obtuse pale, which bears on 

 the middle of its back a short awn scarcely exceeding its apex; anth. oblong, 

 yellow. 1^. Native in Ohio to Minn. (Lapham) and I1L Jn. Aug. (A. geni- 

 cularus, 3. Ed. 2d.) 



11. PHLEUM, L. CAT-TAIL GRASS. (Gr. <f>te6$ ; used by the an- 

 cients probably for a different plant.) Glumes 2, equal, carinate, much 

 longer than the pales, rostrate or mucronate ; pales 2, included in the 

 glumes, truncate, awriless. Compound spikes cylindric, very dense. 



1 P. pratense L. TIMOTHY or HERD'S GRASS. Culm erect, simple, terete, 

 smooth, 2 4f high ; Ivs. linear-lanceolate, flat, glaucous, roughish ; sheaths stri- 

 ate, smooth ; stip. obtuse, lacerated ; gls. cuspidate, in a dense, long, cylindric, green 

 spike; anth. purple; stig. white. This is probably the most valuable of all 

 grasses. It is extensively cultivated in X. Eng., Mid. and W. States, but it faila 

 further South. Jn., JL Eur. 



2 P. alpinum L. MOUNTAIN HERD'S GRASS. Culm about If high, simple, erect: 

 Ivs. shorter than the sheaths, broad and clasping at base, acute at apex, smooth ; 

 sheaths inflated; spicate pan., oblong-ovate, very short (4 to 5" long); gls. truncate, 

 mucronate, with a fringed keel; awns as long as the glumes. i( Alpine regions 

 of the White Mts., K H. Also native of Arc. Am. 



12. ARISTTDA, L. BEARD GRASS. POVERTY GRASS. (Latin arista, 

 an awn ; characteristic of the genus.) Panicle contracted or racemous ; 

 spikelets 1-flowered, flower stipitate ; glumes 2, unequal ; pales pedi- 

 cellate, lower one with 3 awns at the tip, upper one very small, awn- 

 less ; ovary stipitate ; scales 2, entire ; stamens 3 ; stigma plumous. 



Awns twisted-confluent below, anil jointed to the pale, very long No. 9 



Awns distinct below and not jointed to the pale. (*) 



* Awns about equal and divaricate, thrice as long as the flower Nos. 7, 8 



twice as long as the flower Nos. 6, 7 



as long as the flower Nos. 4, 5 



* Awns unequal, the 2 lateral twice shorter (6'0 and suberect No. 3 



* Awns very unequal, the 2 lateral 4 times shorter (2") and erect Nos. 1, 2 



1 A. dichotoma MX. Caespitous ; culm dichotomously branching above ;, pani- 

 cle contracted-racemous ; gls. 3 to 4" long; lateral awns very short, erect, the 

 intermediate one nearly as long as the pales (3"), spreading, contorted. 1 A 



der grass, in sandy soils, U. S., common. Culms 8 12' "high, branching at each 

 joint Lvs. very narrow, with very short, open sheaths, and a very short stipule. 

 Spikelets slender, on clavate peduncles. Aug. 



2 A. ramosfssima Engelm. Culms diffuse, tufted ; rac. loose-flowered, simple, 

 slender ; glumes with short awns, 3 or 5-veined ; lower pale about as long as the 

 glumes (7 to 9''). lateral awns short (2") erect, middle one spreading, 1' long. (D 

 Dry places, III (Engelm.) 



