328 POACE.E. 



Siberia. When tniiture the panicles breaiv away and are carried for 

 long distances by the wind. 



12. A. perennans (Walt.) Tuckerni. Am. .lourn. Sci. (II.)45: 

 44(18413). TmxGuAss. (Joniucopicp perennans WnM. Fl. Carol. 

 73 (1788). Tnchodium derunihens Miciix. V\. Bor. Am. 1:42 

 (1803). T. perennans Ell. Hot. S. C. i^ (la. 1 : !l'.t (1823). 



Culms weak, slender, erect from a decumbent base, 30-00 cm. 

 high. Sheaths smooth, about the lengtli of the internodes; ligulo 

 3-4 mm. long; bhides flat, thin, scabrid, the upper 10-15 cm. 

 long, 2-4 mm. wide. Panicle often included at the liase, dilTusc, 

 pale green, 10-18 cm. long; rays ca[)illary in clusters of 2-4-10, 

 the clusters 3-4 cm. distant, some rays G cm. long, dividing and 

 flower-bearing from near the middle. Spikelets acuminate, scabrid 

 on the keels, 2-2.5 mm. long; first glume the longer; llond glume 

 thin, awnless or rarely short-awned, 1.7 mi!'., long, truncate-toothed, 

 5-nerved; palea or minute. Nearly allied to A. Iii/cnia/is. 



Damp shade; July, August, New England, Michigan, to Texas. 



13. A. Diegoensis Vasey, Hull. Torr. (Mub. 13 55 (ISSC). A 

 foUom Wasey, Bull. Torr. Club, 10:03 (1883). A. nxdtindniis 



Vasey in numerous distributions. 



Culms smootli or scabrid, stout, 60-100 cm. high, sometimes 

 with rootstocks. Ligule acute. 4 mm. long; blades of the culm 

 about 5 in nuinber, erect, scabrid, flat, or involute, 10-18 cm. long, 

 2-4 mm. wide. Panicle lanceolate, 15-20 cm. long, light green ; rays 

 erect in clusters of 5-10, the lower clusters 3-5 cm. distant, the 

 longest ray 5 mm. long and flower-bearing above the middle, the 

 shorter bearing si)ikelets to the base. Spikelets 2.5-3 mm. long; 

 flrst glume vscal)ri(l on the keel, ovate-acute, second smooth, shorter, 

 1-3-nerved; floral glume broad-oval when ^itread, ol)tuse, minutely 

 scabrid, 1.8-2 mm. long, 4-nerved above, awn near the middle, 

 minnte or obsolete, hairs at the base very few and short: palea 0. 



"The panicle resembles that of A. alba, but is narrower, 

 shorter, and more closely flowered." Vasey. 



Washington, JfoireU; Oregon, Bolander; California, Orrutt. 



14. A. Scouleri Trin. Mem. Acad. St. Petersb. (VI.) 0:329 

 (1845). A. repens Scribn., not Sincl. 



