634 



I'OACK.K. 



Bmail. A low slender annuul with .short, mirrow bhuUs. Spike 

 tcrniinul, sltMuicr, llrm, Htruight, slijjhtly coinpniHHi'd. Its iitliiiitios 

 nro with Lc/diinix, Kmlikia ami Psihiniff. 



A jjeims iminiid I'or Prof. I', liiimsoii Scribiier Ity Knioat 

 lluckol, and by ThiirlMT iiK'liub'd in Lijifiinis. 



1. S. Bolanderi ('riiurl>.). Hack. 1. c. Lvjihinis liiibnidvii 

 Thurb. I'loc. Am. Awid. 7: 101. 

 Tho rhuracters of liii' \ii'\\m. 

 Calironiiii and Oregon. 



140. ('^(5t)). AOROPYRON J. (Ja'itn. Nov. Comm. Petrop. 14: 

 (I) 5:5!) (1T70). Aiilliosarhtu' SteiHl. Syn. IM. (inim. 237 (ISoD). 

 JJraconoim Codr. I.e. Ed. l.:5 : ltd (1844). ('o.s/ia Willk. 



Hot. Zoit. :577 (1S5S). f'rentopi/ritm Sclmr, 

 Enuni. PI. Transs. 807 (ISOO). Cfi/hopi/nua 

 lloi-t. Pnig. Steud. Syn. PI. (Irani. ^44 

 (1855). J-Uiilriijia Desv. Nonv. liuU. Sou. 

 Pliiloni. '^: l!iO (1810). J'Jrcmo/ii/rinn Janb. 

 & Spucb, Illustr. PI. Or. 4:!.m; (IS.V)-',:]). 

 Jlayiialdia Sduir, Ennm. PI. 'J'ranss. 807 

 (180G). J/e/ertnifheJiiiin lloclist. Jaul). & 

 Spacli, Illustr. PI. Or. 4:24 (1850). hWr/- 

 neria C. Kocli, Linna'a, 21 : 41 :5 (184S). Se- 

 mUdiiim Schnr, Verb. SielK'ub. Yer. Natnrw. 

 4:01 (185:1). 



Spikelots;J-8-llowc'red, comprossod, sessile 

 at each joint of the simple spike, distichous, 

 turning one side or sometimes oblicpie to the 

 rucbis, racbilhi often articulate between the 

 flowers, which are perfect or the upper im- 

 perfect. Empty glumes rounded on the buck, 

 not inflated, narrower than the lloral and 

 Pig. 120.-5m6nma7?.- witli fewer nerves; floral glumes firm, round 



lamhri. A, spikolet ; on the back, very little if at all keeled, 5-7- 



a. floret ; d, grain. , , . ^ l\ 



(ScribMcr.) nerved, obtuse, acute, or the upper nerves 



extending into an awn, the upper smaller, often emi)ty or enclosing 



an imperfect flower; palea shorter (sometimes longer) than the 



