GRASSES OF IOWA. 



41 



Spikelets subsessile or shortly pedicellate along the continuous 

 rachis of the main axis, i-flowered, hermaphrodite. Empty glumes i, 

 strongly compressed, keeled, awnless, coriaceous, inclosing the much 

 smaller flowering glume. Stamens 3. Styles distinct; stigmas plumose. 



Fig. 29. Osterdamia matrella. a, Spikelet with 6tigmas protruding; a smaller spikelet ; 

 b, second glume ; c, palea; d, stamens. Div. Agros. U. S. Dept. Agrl. 



Grain included in the slightly indurated outer glume, free. Creeping or 

 stoloniferous grasses with rather rigid, often sharp-pointed leaves, and 

 slender, terminal spikes. 



