604 GR AMINES. (grass FAMILY.) 



lower smaller ; flowering glume membrauaceo-herbaceous, with a delicate sca- 

 rious margiu, compressed-keeled, pointless, 5-nerved (the intermediate nerves 

 more obscure or obsolete), the principal nerves commonly clothed with soft 

 hairs at and toward the often cobwebby base ; palet membranaceous, 2-toothed. 

 Stamens 2 or 3. Stigmas simply plumose. Grain oblong, free. — Culms 

 tufted, from perennial roots, except n. 1. Leaves smooth, usually flat and 

 soft. {U6a, an ancient Greek name for grass or fodder.) 



* Low and spreadmfj (3-6' high) from an annual or biennial root, flaccid; 



branches of the short panicle single or in pairs. 



P. ANNUA, L. (Low Spear-Gkass.) Culms flattened; panicle often 1- 

 sided, usually short and pyramidal, sometimes more slender (P. cristata, 

 Chapm.) ; spikelets crowded, very short-pedicelled, 3-7-flowered. — Culti- 

 vated and waste grounds, everywhere. April -Oct. (Nat. from Eu.) 



* * Low; the culms (6-20' long) geniculate-ascendinrj from a running rootstock , 



rigid, verij much flattened ; panicle simple and contracted. 



P. coMPRESSA, L. (Wire-Grass. English Blue-Grass.) (PI. 10, fig. 

 1-4.) Pale, as if glaucous; leaves short; panicle dense and narrow, some- 

 what one-sided (1 - 3' long), the short branches mostly in pairs ; spikelets almost 

 sessile, 3- 10-flbwered, flat. — Dry, mostly sterile soil, in waste places; rarely 

 in woods. (Nat. from Eu.) 



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



•1- Soft and flaccid, smooth or nearlij so, even to the branches of the panicle ; leaves 



short and flat, short-pointed ; ligule elongated. 



1. P. alpina, L. Culms rather stout (8 - 14' high) ; leaves broadly linear, 

 especially those of the culm ( 1| - 2' long, H - 3" wide) ; panicle short and broad ; 

 spikelets broadly ovate, 3 - 9-flowered (about 3" long) ; flowering glume vil- 

 lous on the midrib and margins. — N. Maine (?), Isle Koyale and north shore 

 of Lake Superior, and northward. (Eu.) 



2. P. laxa, Haenke. Culms slender (4 - 9' high) ; leaves narrow ; panicle 

 somewhat raceme-like, narrow, often one-sided and nodding ; spikelets 2 - 4-flow- 

 ered, one half smaller. — Alpine mountain-tops of Maine, N. H., and N. New 

 York, and high northward. (Eu.) 



-*- -*- More strict and rigid, roughish, especiallg the panicle ; ligule short. 



3. P. nemoralis, L. Culms 6 - 20' high ; leaves narrow, short, soon in 

 volute ; branches of the panicle 2-5 together, very scabrous ; spikelets purplish 

 (or sometimes pale), 2-5-flowered; lower glumes ovate-lanceolate and taper- 

 pointed, the flowering lanceolate, somewhat webby at base, villous on the keel 

 and margins below the middle, its nerves obscure. (P. ca?sia, Smith.) ^ The 

 more common form has a usually narrow somewhat nodding panicle, wit\ short 

 ascending branches, the small pale or purplish spikelets 2-flowered. Lab. to 

 N. Maine and N. Vt. ; Lake Champlain (Pringle) ; N. shore of L. Superior 

 to N. Iowa, and westward. — A form with somewhat stouter and stricter habit, 

 the darker or often pale spikelets 3-5-flowered (P. cassia, var. strictior. Gray), 

 corresponds nearly to the European P. casia. High mountains of N. H. and 

 Vt., and Gardner's Island, L. Champlain ( C. E. Faxon), Isle Royale and N. 

 shore of L. Superior, and westward. — Also a form with the branches of the 

 short panicle broadly divaricate; N. Wise. [Laphavi). (Eu.) 



