GRASSES OF IOWA. 



233 



DESCRIPTION. 



Southern Spear Grass. An annual, s to itt inches (1-4 dm.) 

 high, with the erect or ascending stems diffusel) branching near tin 

 base. Sheaths pilose at the throat, otherwise smooth, leaf-blade 1 to 7 

 lines (2-14 mm.) long; \ to \\ lines (1-3 mm.) wide, conduplicate 

 when dry. Panicle oblong-lanceolate to pyramidal, 3 to 8 or 12 inches 

 Hi or 24 cm.) long, the widely spreading primary branches solitary 



PlG. 163, Era</rostis Purshii—a., b, c, spike- Flo. 164. Eragroilis pectinacea -a. b, c, 

 lets. ( Oiv. Agros. U. S. Dept. Agrl. ) spikelets. (,Div. Agros. U. S. Dept. Agrl. ) 



or two to three together, the axils not pilose. Spikelets narrow-lanceo- 

 late, 2 to 4.I lines (4-9 mm.) long, three to fifteen-flowered, appressed 

 to the branches, nearly equalling or exceeding their capillary pedicels; 

 empty glumes ovate, acute, scabrous on the keel, the longer upper one 

 ability, line (1 mm.) in length; flowering glume broadl) ovate, obtuse, 



