54 



POACEAE 



2. A. atrata Rydb. A somewhat tufted perennial; stems 1.5-3 dm. high, 

 few-leaved, more or less bulbous at the base; leaf-blades 5-10 cm. long, about 2 

 mm. wide, flat, smooth; panicle 5-8 cm. long; empty glumes nearly equal- 

 lemma nearly as long, obtusish. Mountains: B.C. Moni.—Subalp. 



1 ?' -f^- Jliurberiana Hitchc. Tufted perennial; stem 2-4 dm. high, 

 leaiy; leaf-blades 5-10 cm. long, 2 mm. wide, lax, light green; panicle more or 

 less droopmg, 5-20 cm. long; empty glumes about 2 mm. long, narrow, gradually 

 acute; lemma nearly as long, obtuse, faintly 5-nerved. Meadows: B.C.— Mont. 

 — Utah — Cahf. Submont. — Subalp. Jl-Au. 



. *"o^o stolonifera L. Perennial, with a long creeping rootstock and stolons; 

 stem 2-8 dm. high; leaf-blades 5-10 cm. long, 3-4 mm. wide, light- or glaucous- 

 green, scabrous; panicle interrupted, 3-10 cm. long; empty glumes obtuse, 

 scabrous on the keel and back, 2 mm. long; lemma about half as long, a^vmless, 

 .truncate and toothed at the apex. A. verticillalaYiU. Wet meadows: Tex.— 

 Utah— Cahf.; Mex., C. Am., S. Am., Eu., Africa and Asia. Son.~Sub?nont. F-0. 



5. A. alba L Tufted perennial; stems 2-15 dm. high, erect or decumbent 

 at the base; leaf-blades 4-15 cm. long, 3-8 mm. wide; panicle upright, 5-30 cm. 

 long, with spreading branches, tho lower usually vcrticillate; empty glumes 2-3 

 mm long, pale or purplish nearly equal, acute; lemma two-thirds to three- 



i?^*^i^^ ■^' obtuse, seldom awned. Wet meadows: Newf.—Fla —Calif — 

 B.C.; Eurasia. Plain—Sub mont. Je-0. 



}.J'A' ^^^ilis ,^\sey. Tufted perennial; stems 1-4 dm. high, slender, 1-3- 

 leaved , leaves mostly basal; leaf-blades 2-10 cm. long, 1 mm. wide or less, usually 

 conduphcate ; panicles 2-0 cm. long; branches ascending; empty glumes equal, 

 abruptly pointed, 1.5-2 mm. long, purple; lemma nearly as long, awnlcss. High 

 mountains: B.C.— Ore.— Colo.— Wyo. M ont .—Alp . Au^O . 



af I' t* '^^Prfssa Vasey Tufted perennial; stems decumbent and geniculate 

 at the base 1 o 2.5 dm. high, slender, leafy below; leaf-blades 3-5 cm. long, 1 



l^n. I ,' f ' ^^""'t. ''^''■°''^' ^-^ ^"'- ^«"-' '" ^Se open; empty glumes 2 mm. 

 S^-^if™ °' "'^"^tely dentate at the apex. Mountains: Colo. 



Irn5' 1^' ^®P**i^^ ^y?^- Cespitose and stoloniferous perennial; stems 2-3 dm. 

 i,^f;ifr''fl T- •''"": ^"^ """?• r^^' fl^t; panicle 3-5 cm. long; branches 



SnfP Wr^? .?"J'^i?° J"'^' the base; empty glumes purplish, niarlv equal, 

 A Ir'n! M ^ 1 %^^'''^r shorter toothed at the apex, often with a minute awn. 

 A. exarata slolomfera Vasey. Bottom lands: B.C.-Calif. Submont. Jl-Au. 



h\2'^t' f^^l^T^ 7 T^^' ■ perennial, with a creeping rootstock; stem 5-10 dm- 

 high leaf-blades 8-15 cm. long, 3-4 mm. wide; panicles open, but often narrow- 



Pn„;i o'{^^\ ^^^^l^e-'^ ascending, naked below; empty glumes pale, nearly 

 wl^Pdif .^- =' abruptly acute; lemma nearly a. long, obtuse and minutely 

 Sif^'/uli.'^I^X^'^'"^ °^ short-awned. Wet meadows: B.C.^Ida.- 



1 2^Hm^n.^Tln '^™- •7''^*'^'^ perennial; stem 5-15 dm. high; leaf-blades 

 naniclTl 2 d'm Inn"""?- '^''^^' ^f^ scabrous, abruptly contracted at the ligules; 

 nX f.n?rin^;h^^' ''''''''' contracted; empty glumes about 3 mm. long, |rad- 

 two thirds ^f tnl' Tf''' ^'g'^t green, scarious-margined; lemma one-half to 

 S!if.^"pL-:-&. ISl." ^'' "^"''^"^^ B.C.-Mont.-Neb.-X.M. 



11. A. asperifolia Trin. 



om lr>ncr 9 f ^rv. -A .^"'"^"^ 1'^'.^'""^') «ie"i <5-D am. nign; blades &-i£> 



emotv Sump. ^^-JV ^i' ^^^^^o^^? P^^^^le 5-10 cm. long, narrow and dense; 

 Xn tinled wi?h^n^'l^T''''^^*^^'^f- T'"" J^^g, Usually abruptly pointed 

 A e^am/f i-^n.V ^^'^'^^^ two-thirds to three-fourths as long, awnless 



NM-Cair R? ^^P7 ^- ^7'«'"««^« Torr. Wet meadows: Man.-Neb.-^ 

 vi.Mi. i^alit. — hs.O. Plain — Moiit. Je-Au. 



erec^t^'lptf hlSlf/r^^^' i ^^^^P^tose perennial; stem about 1.5 dm. high, smooth, 

 dpni- r ^ "^^ M *'"'• '°''- ^^t, 2 mm. wide; panicle oblong. 2-A cm long 

 dense, branches nearly erect, 1-2 cm. long, very 'scabrous; empty glumes 2 mm 



