298 MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



FIGURE 590. Distribution of 

 Avena hookeri. 



58. ARRHENATHERUM Beauv. 



Spikelets 2-flowered, the lower floret staminate, the upper perfect, 

 the rachilla disarticulating above the glumes and produced beyond 



the florets; glumes 

 rather broad and 

 papery, the first 1- 

 nerved, the second 

 a little longer than 

 the first and about 

 as long as the spike- 

 let, 3-nerved; lem- 

 mas 5-nerved, hairy 



on the callus, the lower bearing near the 

 base a twisted, geniculate, exserted awn, 

 the upper bearing a short straight slender 

 awn just below the tip. Rather tall per- 

 ennials, v with flat blades and narrow 

 panicles, 'Type species, Arrhenatherum 

 avenaceum Beauv. 

 (A. elatius). Name 

 from Greek arren, 

 masculine, and 

 other j awn, refer- 

 ring to the awned 

 staminate floret. 



1. Arrhenathe- 

 rum elatius (L.) 

 Mert. and Koch. 

 TALL OATGRASS. 

 (Fig. 592, A) 

 Culms erect, 1 to 

 1.5 m tall; blades 

 flat, scabrous, 5 to 

 10 mm wide; pani- 

 cle pale or purplish, 

 shining, 15 to 30 

 cm long, the short 

 branches verticil- 

 late, spreading in 

 an thesis, usually 

 spikelet-bearing from the base; spikelets 7 to 8 mm long; glumes mi- 

 nutely scabrous; lemmas scabrous, the awn of the staminate floret 

 about twice as long as its lemma. 9J. Meadows, open ground, and 

 waste places, Newfoundland to British Columbia, south to Georgia, 

 Tennessee, Iowa, Idaho, and California; frequent in the Northern and 

 Eastern States ; introduced from Europe and escaped from cultivation. 

 Cultivated in the northern humid regions as a meadow grass. 



ARRHENATHERUM ELATIUS var. BULB6suM (Willd.) Spenner. ^ TU- 

 BER OATGRASS. (Fig. 592, B.) Base of culm consisting of a series of 

 closely approximate corms (shrot subglobose internodes) 5 to 10 mm 

 in diameter. 9[ Occasionally introduced, Michigan, Virginia to 

 Alabama. Europe. 



FIGURE 589. Avena hookeri. Panicle, 

 X.I; floret, X 5. (Scribner 372, Mont.) 



FIGURE 591. Avena morto- 

 niana. Panicle, X 1; floret, 

 X5. (Type.) 



