GENUS 44. 



GRASS FAMILY. 



203 



Panicle dense and contracted, spike-like, its branches short and appressed ; a grass of brackish 



marshes and wet sands. 2. A. maritima. 



Palet inconpicuous, minute, or wanting. 



Branches of the contracted panicle short, spikelet-bearing to the base. 3. A, asperifolia. 

 Branches of the panicle slender, naked below. 

 Flowering scale awned. 



Awn flexuous, barbellate, twice the length of the M" spikelet. 4. A. Elliottiana. 

 Awn stouter, glabrous, rigid, usually bent, not twice the length of the spikelet. 

 Branches of the panicle usually ascending; spikelets i" long. 



Culms 6' tall or less; panicle i' long or less; alpine grass. 5. A. rupestris. 

 Culms i-2 tall; panicle exceeding 2' long. 6. A. canina. 



Branches of the mature panicle spreading; spikelets i l /^"-\ l / 2 " long. 



Awn exserted ; panicle branches glabrous or hispidulous. 7_ A. borealis. 

 Awn short ; panicle branches hispid. 8. A. geminata. 



Flowering scale awnless, or very rarely with a short awn. 



Culms weak, decumbent or prostrate at the base; blades lax. 9. A. SchweinitMti, 



Culms and blades erect. 



Branches of the panicle capillary, elongated, usually dividing above the middle, the 



spikelets often crowded at the extremities. 



Spikelets W-i" long; blades short. 12. A. hyemalis. 



Spikelets i^"- 1 /^" long; blades elongated. n. A. altissima. 



Branches of the panicle not elongated, usually dividing at or below the middle. 

 Spikelets about i" long; a grass of low elevations. 10. A. perennans. 

 Spikelets iJ4" ij^" long; a high mountain grass. 13. A. oreophila. 



i. Agrostis alba L. Red-top. Florin. Herd's-grass. Fig. 487. 



Agrostis alba L. Sp. PI. 63. 1753. 



Agrostis vulgaris With. Bot. Arr. Brit. PI. Ed. J 



3, 132. 1796. 



A. alba var. aristata A. Gray, Man. 578. 1848. 

 Agrostis alba var. vulgaris Thurber in A. Gray, 



Man. Ed. 6, 647. 1890. 



Culms 8'-2$ tall, erect or decumbent at the 

 base, often stoloniferous, simple, smooth and 

 glabrous. Sheaths usually shorter than the 

 internodes, often crowded at the base of the 

 culm ; ligule 4" long or less; blades 2'-8' long, 

 i "-3" wide, scabrous; panicle 2' -9' in length, 

 contracted or open, green or purplish, the 

 branches ascending or erect, the lower i'-3' 

 long; spikelets i"-ii" long; outer scales 

 about equal, acute, smooth and glabrous, ex- 

 cept on the hispid or scabrous keel ; third 

 scale shorter, rarely awned near the base, the 

 palet at least one-third its length. 



Fields and meadows nearly throughout North 

 America, extensively cultivated for fodder. Na- 

 turalized from Europe, and perhaps also native 

 northward. White-top ; White, Marsh or Creep- 

 ing Bent ; Black Quitch, Tussocks, Water Twitch, 

 Fine John ; Monkey's, Burden's or Summer 

 Dew-grass ; Conch or Bonnet-grass. July-Sept. 



2. Agrostis maritima Lam. Dense-flowered 

 Bent-grass. Fig. 488. 



.!. maritima Lam. Encycl. i: 61. 1783- 



Agrostis coarctata Ehrh. ; Hoffm. Deutsch. Fl. Ed. 2, 



i : 37. 1800. 

 A. alba maritima Meyer, Chloris Hanov. 656. 1836. 



Glabrous. Culms tufted, erect, or decumbent at 

 the base and often rooting at the lower nodes, 

 smooth, i2'-2o' tall, at length branching; sheaths 

 shorter than the internodes; ligule scarious, -\ t 

 long; blades erect, rough on both surfaces, li -3* 

 long, li" or less wide; panicle dense and con- 

 tracted, i*'-4' long, i'-i' thick, its branches erect, 

 the longer li' long or less; spikelets numerous, 

 crowded, acute at both ends and lanceolate when 

 closed, i"-ii" long, on shorter hispidulous pedicels 

 which are much thickened at the apex ; empty scales 

 acute, hispidulous on the upper part of the keel, 

 especially in the first scale; flowering scale hyaline, 



^ , about three-quarters as long as the spikelet, den- 



ticulate at the truncate or rounded apex; palet about one-half as long as the scale. 



