50 POACEAE 



24. ALOPECtTRUS L. Foxtail. 



. Annuals or perennials. Inflorescence a cN'lindric dense spike-like panicle. 

 Spikelets articulate under the empty glumes, 1-flowered, compressed; flower per- 

 fect. Empty glumes 2, acute, sometimes short-awned, more or le.ss united at 

 the base, compressed-keeled. Lemma hyaline, obtuse, with a dorsal awn or 

 point, their margins usually more or less united at the base. Stj'les distinct or 

 nearly so; stigmas long, sub-plumose. 



Awn about twice as long as the lemma. 



Spikes 8-12 mm. thick; empty ghmies 3.5-4.5 mm. long, abruptly acuminate. 



1. A. occidentalis. 

 Spike about 5 mm. thick; empty glumes about 3 mm. long, obtuse. 



Stem erect, 3-5 dm. high, slightly if at all geniculate at the base, pale: ligules 



4-5 mm. long, acutish. " 2. A. pallescens. 



Stem decumbent, and geniculate at the base, 1-1.5 dm. high; ligules 2 mm. long, 

 obtuse. 3. A. Macounii. 



Awn scarcely e.\ceeding the lemma. 



Stem erect, 1.5-5 dm. high; spike cjiindric, obtuse. 4. A. aristulalus. 



Stem geniculate at the base, 1-5 cm. high; spike oblong, acute. 5. A. caespitosus. 



1. A. occidentalis Scribn. & Tweedy. Perennial, with a rootstock; stem 

 erect, 2-10 dm. high; leaf-blades 5-15 cm. long, 4-7 mm. wide, flat, iscabrous on 

 the veins above; spike 2-3 cm. long; empty glumes equalling or slightly exceed- 

 ing the obtuse lemma, which is scabrous and ciliate near the tips; awn 6 mm. long, 

 twisted below, bent at the middle, attache'd near the base of the gkmie. Wet 

 meadows: Alta. — Colo. — ^Utah — Ida. Monl. — Subalp. Je-Au. 



2. A. pallescens Pii)er. Somewhct tufted perennial, pale green; blades 

 flat, 6-12 cm. long, 2-6 mm. wide, strongly scabrous above; spike exserted, pale, 

 2-7 cm. long; empty glumes strongly ciliate on the keel, obtuse; lemma as long 

 as the empty glumes, obtuse; awn nearly basal, about 5 mm. long. Wet mead- 

 ows: Wash. — Mont. — Ida. Submont. My-Je. 



3. A. Macounii Vasey. Somewhat cespitcse perennial; blades 1-5 cm. 

 long; spike 1-3 cm. long, 5 mm. thick; empty gkmies ciliate on the keel, smooth 

 on the sides, obtuse; lemma slightly shorter, glabrous, ovate-oblong, obtuse; 

 awn nearly basal, bent at the middle, 6-8 mm. long. A. geniculatus caespitosus 

 Scribn. Rocky places: Sask. — B.C. Boreal — Mont. My-Je. 



4. A. aristulatus Michx. Somewhat tufted perennial; leaf-blades 5-15 

 cm. long, 3-4 mm. wide, scabrous, especially above; spike 3-8 cm. long, 4-6 mm. 

 thick; outer glumes 2-2.5 nmi. long, acutish; lemma somewhat shorter, obtuse, 

 glabrous; awn inserted at or near the middle. A. (jeniculatus Am. auth., not L. 

 A. fulvus Am. auth., not Smith. Wet meadows: Me.^ — ^Pa. — Calif. — Alaska. 

 Plain — Subalp. Je-S. 



5. A. caespitosus Trin. Cespitose perennial; leaf-blades flat, less than 2 

 cm. long, 1 mm. wide; sjjike 0.5-1.5 cm. long, 3-4 mm. thick, acute; outer glumes 

 2 mm. long, acutish; lemma nearly as long, obtuse; awn inserted near the base. 

 [Perhaps a depauperate form of the preceding.] Wet places: Canadian Rockies 

 — N. W. Coa.st. 



25. PHIPPSIA R. Br. 



Tufted annuals. Inflorescence a narrow panicle. Spikelets 1-flowered; 

 flowers perfect. Empty glumes 2, minute, or the first one wanting. Lemma 

 thin-membranous, keeled. Palet shorter, 2-keeled. Stamens 1, rarely more. 

 Styles short, distinct; stiginas short-i)lumose. Grain enclosed in the lemma and 

 the palet, which splits and lets it drop. 



1. P. algida (Solander) R. Br. Stems 2-10 cm. high, erect or ascending; 

 sheaths short, loose; leaf-blades 1-2 cm. long, 0..5-2 mm. wide, obtuse; panicle 

 0.5-3.5 cm. long, narrow; spikelets 1-1.5 mm. long; emi)ty glumes minute or the 

 first one wanting; lemma thin, 1-nerved, obtuse or truncate and somewhat 

 erose. Arctic-alpine situations: Greenl. — Alaska; Colo.; arctic Eurasia. Alp. 

 Jl-Au. 



26. BLEPHARONEURON Nash. 



Tufted perennials. Panicles open, loosely flowered. Spikelets 1-flowered. 

 Empty glumes membranous, 1-nerved, .smooth, the first shorter and narrower 



