HOW TO KNOW THE GRASSES 



TRIBE III. HORDEAE 



la. One spikelet borne at each node of the rachis 2 



lb. Two or more spikelets borne at some or all of the nodes of the 

 rachis (some spikelets may be reduced to awned rudiments). .. 10 



2a. Rachis not breaking up at maturity, the joints thin and flat 3 



2b. Rachis breaking into individual joints at maturity; joints much 

 thickened at their upper ends; spikes cylindrical. Fig. 159. 



GOATGRASS Aegilops cylindTica Host 



Annual; tufted; 40 — 60 cm. tall; much branched 

 from the base, one plant bearing as many as 

 60 spikes; spikes 5 — 10 cm. long; joints of the 

 rachis 6 — 8 mm. long, the spikelets slightly 

 longer and fitting closely into the contour of 

 the joints; spikelets glabrous or hairy, with 2 — 5 

 florets; lower spikelets nearly awnless, the up- 

 per ones bearing awns up to 5 cm. long; glumes 

 thick and stiff, bearing a pronounced tooth at 

 one side of the awn. Goatgrass was presum- 

 ably introduced into the Middle West in Turkey 

 wheat brought to the United States by Russian 

 immigrants in the 1870's. The plants are winter- 

 annual, beginning growth in the fall and seed- 

 ing out from May to July. They crowd out wheat 

 when they are numerous. The seeds travel as 

 contaminants in wheat seed. 



Aegiiops tTiuncialis L. is similar but has three 

 awns on each glume. It is a bad weed on 

 range land in California; introduced from Europe. 



Figure 159 



5a. Spikelets placed flatwise against the rachis; both glumes present . . 4 



85 



