312 GRAMINE.E. Poa. 



2. Hoot perennial : flowers perfect. 

 * Low mountain or alpine species, erect in perennial tufts. 



H- Soft and flaccid, smooth or nearly so ; leaves short and flat, short pointed ; 



ligule elongated. 



2. P. alpina, Linn. Culms 6 to 18 inches high, rather stout: leaves broadly 

 linear, 1| to 2 inches long, the upper very short, mucronate : panicle oblong or 

 pyramidal, 1 to 3 inches broad ; spikelets broadly ovate, 3 - 9-flowered, 2 or 3 lines 

 long : glumes ovate, acute : lower palet very hairy below, especially on the mid- and 

 marginal nerves. Reichenb. Icon. Fl. Germ. t. 156; Gray, Man. 629; Watson, 

 Bot. King Exp. 386. 



This and the two following species, though not occurring in any of the collections made within 

 the State, are frequent in the mountain ranges at the north and east, and are very likely to be met 

 with. It presents a great variety of forms, and when unexpanded appears very different from the 

 fully developed plant. 



H -i- Leaves narrowly linear or setaceous. 



3. P. lax a, Haenke. Culms 3 to 10 inches high, very slender, somewhat com- 

 pressed : leaves narrowly linear, obliquely mucronate : panicle 1 to 3 inches long, 

 narrow, lax, one-sided and often nodding, its branches solitary or in pairs ; spikelets 

 2 4-flowered, 2 lines long, or less : glumes acuminate-pointed : florets hairy on the 

 keels and margins. Reichenb. Icon. FL Germ. t. 157. 



In the Rocky Mountains (Parry, Bourgeau) ; eastward to the mountains of New York and New 

 England. 



4. P. abbreviata, R. Br. Culms from slender creeping rootstocks, 3 to 6 inches 

 high : leaves convolute, filiform-setaceous, those of the copious radical tufts mostly 

 reaching the panicle, the culm-leaves about an inch long, smooth or finely puberu- 

 lent near the apex ; ligule oblong, entire ; sheaths very loose : panicle about an inch 

 long, its very simple 1 - 2-flowered branches in pairs, nearly smooth ; spikelets 

 2 to 2^ lines long, 3 5-flowered: glumes about half as long as the florets, acute, 

 rough on the keel; florets rather distant : lower palet 1 lines long, strongly keeled, 

 with the other nerves conspicuous, rough-pubescent all over except the broad-scarious 

 margins, more or less woolly at base. App. to Parry's 1st Voy. 187 ; Steud. Syn. 

 Gram. 253. 



Washington Territory (Pickering) ; Arctic America. 



* * Tall perennials (1 to 3 feet) with open oblong or pyramidal panicles, the 

 rather short and rough branches mostly in fives : florets acute, more or less 

 webbed at base. Meadow grasses introduced by cultivation or (except n. 6) 

 indigenous. 



- Culms with running rootstocks, and emitting stolons from the base. 



5. P. pratensis, Linn. Culm and sheaths smooth ; leaves dark green, the radi- 

 cal very long, those of the culm short, scabrous on the margins ; ligule short and 

 blunt : panicle pyramidal ; spikelets 3 - 5-flowered, somewhat crowded and almost 

 sessile : glumes acuminate, scabrous on the keel : lower palet distinctly 5-nerved, 

 silky-hairy on the margins and keel and webbed at base. Reichenb. Icon. Fl. 

 Germ. t. 161. 



Near San Francisco (Bolandcr) ; northward to Oregon and Washington Territory and indi- 

 genous in the mountainous districts eastward to New England. This, known as "June Grass," 

 "Green Meadow Grass," "Spear Grass," and "Kentucky Blue Grass," in various parts of the 

 country, is one of the most highly valued pasture and meadow grasses. The limestone soils of 

 Kentucky being especially favorable to its development, the " Kentucky Blue Grass" was for a 

 long time supposed to be a distinct species, until it was found that seed from the celebrated ' ' Blue- 

 grass" pastures of that State when sown elsewhere produced only "June-grass." In Oregon this 

 is regarded as one of the most troublesome weeds in cultivated fields, its rapid propagation by 

 means of rootstocks and stolons, so useful when the grass is cultivated, making it very difficult to 



