30 



THE SEEDS OF THE BLUEGRASSES. 



inflistinct or evident only below the middle; keel and marginal veins silky pubescent 

 below the middle or higher on the keel, which is hispid at the apex; surface between 

 the marginal veins and keel appressed pubescent at the base; web wanting; palea 

 nearly or quite equal to the glume, its keels not arched as in Poa annua, slightly 

 silky pubescent below the middle and hispid-ciliate above; rachilla segment glabrous, 

 varying from no longer than wide to one-third the length of the glume; aborted 

 floret of the sterile rachilla segment minute; grain 1^ mm. long, keeled and grooved, 

 semitranslucent, dark reddish brown, granular. (Fig. 12.) 



/ y 



Fig. 12. — Seeds f>f alpine meadow grass (Poa alpina): a and b, back views; r-e, side views; /-/(, front 



views; h, a terminal floret. 



The seed of Poa alpina is not on the market and is not likel}^ to be 

 found in commercial seeds. Individual seeds of I\ aljjina closely 

 resemble those of P. annua^ but are.to be distinguished b}^ the indis- 

 tinct intermediate veins of the olume, the variable rachilla segment, 

 and especially by the keels of the palea, which are slenderer, not 

 arched, less pubescent, and strictly hispid-ciliate above. The plant is 

 alpine and occurs in the northern part of the United States as far 

 west as Colorado, in Canada and Alaska, and in Europe and Asia. 



Poa sudetica Haenke. 



Spikelets 2 or 3 flowered; florets 3—4 mm. long, lanceolate or ovate-lanceolate; 

 apex acute or acuminate; glume somewhat arched and strongly keeled at the back, 

 light brown or dark brown, sometimes tinged with purple; margins of the glume 

 narrowly infolded below the middle, narrowly hyaline-edged above the middle and 

 not flaring at the apex; all the veins distinct, never silky pubescent, usually hispid; 



Fig. 13. — Seedsof Poa sudetica: a and 6, back views; c-e, side views; /and ci. front views: a, a. terminal 



floret. 



general surface scabrous or sometimes glabrous; web not present; palea equaling or 

 somewhat exceeding the glume and often separated from it at the apex in florets 

 having a well-developed grain; keels of the palea hispid-ciliate, mostly exposed and 

 more or less evident from the side; rachilla segment varying from one-fifth to one- 

 third or even one-half the length of the glume, glabrous or scabrous, sterile rachilla 



