GRAMINEAE. 



VOL. I. 



10. Poa crocata Michx. Wood Meadow-grass. 

 Northern Spear-grass. Fig. 613. 



Poa caesia var. strictior A. Gray, Man. Ed. 5, 629. 1867. 

 P. crocata Michx. Fl. Bor. Am. i : 68. 1803. 



Culms 6'-2 tall, erect, simple, slender, sometimes 

 rigid, smooth and glabrous. Sheaths usually shorter 

 than the internodes; ligule i"-i" long, truncate; blades 

 i '-4' long, i" wide or less, erect, smooth or rough; 

 panicle 2' -5' in length, open, the branches erect or 

 ascending, rarely spreading, i'-2' long; spikelets 2-5- 

 flowered, ii"-2i" long; lower scales acute or acumi- 

 nate, i-3-nerved ; flowering scales obtuse or acute, 

 i"i\" long, faintly 5-nerved, somewhat webby at base, 

 the midnerve and the marginal nerves silky-pubescent 

 on the lower half. 



Labrador to Yukon, Vermont, Minnesota and Alberta, and 

 in the mountains to Colorado and Arizona. June-Aug. 



Poa nemoralis L., a grass of Europe and Asia, may be 

 found as an occasional introduction. It may be distin- 

 guished from the above by its much narrower empty scales. 



ii. Poa triflora Gilib. False Red-top. 

 Fowl Meadow-grass. Fig. 614. 



Poa serotina Ehrh. Beitr. 6 : 83. Name only. 

 P. triflora Gilib. Exercit. 531. 1792. 



1791. 



Culms i J-5 tall, erect, simple or rarely branch- 

 ed, smooth, glabrous. Sheaths usually shorter 

 than the internodes, smooth and glabrous; ligule 

 i "-2" long; blades 2' -6' long, i"-2" wide, smooth 

 or rough ; panicle 6' -13' in length, open, the 

 branches spreading or ascending, 2'-$' long, di- 

 vided and spikelet-bearing above the middle; 

 spikelets 3~5-flowered, ii"-2" long, exceeding 

 their pedicels ; lower scales acute, glabrous, rough 

 above on the keel, the lower usually I -nerved, the 

 upper 3-nerved ; flowering scales obtuse, some- 

 what webby at the base, i"-ii" long, silky-pubes- 

 cent on the lower half of the marginal nerves and 

 the midnerve, the intermediate nerves obscure or 

 wanting. 



In swampy places, Newfoundland to Vancouver Island, south to New Jersey and Colorado. 

 Also in Europe and Asia. Duck-grass. July-Aug. Formerly confused with Poa flava L. 



12. Poa pratensis L. Kentucky Blue-grass. 

 June-grass. Fig. 615. 



Poa pratensis L. Sp. PL 67. 1753. 

 P. pratensis var. angitstifolia Ki 

 1833- 



PI. 67. 1753. 



ignstifolia Kunth, Enum. i : 353. 



Glabrous, culms i-4 tall, from long running 

 rootstocks, erect, simple, smooth. Sheaths often 

 longer than the internodes ; ligule I" long or less, 

 truncate; blades smooth or rough, $"-3" wide, those 

 of the culm 2'-6' in length, the basal much longer; 

 panicle 2i'-8' in length, usually pyramidal, the 

 branches spreading or ascending, sometimes flexuous, 

 i '-3' long, divided and spikelet-bearing above the 

 middle ; spikelets 3-5-flowered, 2"-2^" long, exceed- 

 ing their pedicels ; scales acute, the lower unequal, 

 glabrous, rough on the keel, the lower i -nerved, the 

 upper 3-nerved; flowering scales \\" long, webbed 

 at the base, 5-nerved, the marginal nerves and mid- 

 nerve silky-pubescent below, the intermediate ones 

 naked. 



In meadows, fields and woods, almost throughout North America. Widely cultivated for hay 

 and pasture. Also in Europe and Asia. In North America probably indigenous only in the northern 

 and mountainous regions. Variable. Natural or green-grass. Common meadow-grass. June-Aug. 



