GENUS 103. 



GRASS FAMILY. 



285 



6. Agropyron biflorum (Brignoli) R. & S. Pur- 

 plish Wheat-grass. Fig. 691. 



Triticum biflorum Brignoli, Fasc. PI. Foroj. 18. 1810. 

 Agropyron biflorum R. & S. Syst. 2: 760. 1817. 

 Agropyrum violaceum Vasey, Spec. Kept. U. S. Dept. Agric. 

 63 : 45- 1883. 



Culms 6'-2 tall, erect, simple, smooth and glabrous. 

 Sheaths usually shorter than the internodes; ligule very 

 short; blades 2'-6' long, i"-3" wide, flat or involute, rough 

 or sometimes smooth beneath; spike i'-4' in length, occa- 

 sionally longer, 2"-$" broad; spikelets 3-6-flowered; empty 

 scales broad, usually purplish, scarious on the margins, 

 5-7-nerved, 4"-6" long, acute or acuminate, sometimes awn- 

 pointed, rarely long-awned ; flowering scales often purplish, 

 5-7-nerved, scarious on the margins, 4"-6" long, acuminate 

 or short-awned, the awn rarely as long as the body. 



Nova Scotia to British Columbia, south to the mountains of 

 New England, New York and Pennsylvania, and in the Rocky 

 Mountains to Colorado. Ascends to 5500 ft. in the White 

 Mountains. Also in northern Europe and Asia. Summer. 



7. Agropyron tenerum Vasey. Slender 

 Wheat-grass. Fig. 692. 



A. tenerum Vasey, Coult. Bot. Gaz. 10: 258. 1885. 



Agropyron novae-angliae Scribn. Contr. Bot. Vt. 8: 103. 

 1900. 



Glabrous, culms 2-3 tall, erect, simple, often 

 slender, smooth. Sheaths usually shorter than the 

 internodes, glabrous ; ligule very short ; blades 3'-io' 

 long, i"-2" wide, flat or involute, rough; spike 3'-7' 

 in length, usually narrow and slender; spikelets 3-5- 

 flowered ; empty scales 4"-6" long, acuminate or 

 short-awned, 3~5-nerved, scarious on the margins ; 

 flowering scales 5"-6" long, 5-nerved, awn-pointed 

 or short-awned, scarious on the margins, often rough 

 toward the apex. 



In dry soil, Newfoundland to British Columbia, south 

 to Kansas, Colorado and California. July-Aug. 



8. Agropyron caninum (L.) R. & S. Bearded 



or Awned Wheat-grass. Fibrous-rooted 



Wheat-grass. Fig. 693. 



Triticum caninum L. Sp. PI. 86. 1753. 

 Agropyrum caninum R. & S. Syst. 2: 756. 1817. 

 Agropyrum unilaterale Cassidy, Bull. Colo. Agric. Exp. 



Sta. 12 : 63. 1890. 

 A. Richardsoni Schrad. Linnaea 12: 467. 1838. 



Culms i-3 tall, erect, simple, smooth and gla- 

 brous. Sheaths usually shorter than the internodes, 

 smooth, the lower sometimes pubescent ; ligule short ; 

 blades 3 '-9' long, i"-3" wide, smooth beneath, rough 

 above; spike 3'-8' in length, sometimes one-sided, 

 often nodding at the top ; spikelets 3-6-flowered ; 

 empty scales 4i"-6" long, 3~5-nerved, acuminate, 

 awn-pointed or bearing an awn i"-3" long; flowering 

 scales 4"-5" long, usually scabrous toward the apex, 

 acuminate into an awn sometimes twice their own 

 length. 



New Brunswick to the Yukon, south to North Caro- 

 lina, Tennessee, Iowa and Colorado. Also in Europe 

 and Asia. Native northwnrd : southward locally natu- 

 ralized from Europe. Dog's-tooth grass. July-Aug. 



