372 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



A densely tufted perennial with linear flat erect blades and shining spikelike 

 panicles about 5 to 7 cm. long. 



Arctic regions of the northern hemisphere, extending southward in the moun- 

 tains to the southern hemisphere. Originally described from Lapland. In the 

 West Indies only at high altitudes in Santo Domingo (Constanza, Turckheim 

 3133). 



72. SPHENOPHOLIS Scribn. 



Spikelets 2-flowered ; glumes unequal, falling with the spikelet, the first nar- 

 row, acute, the second cuneate, blunt, becoming subcoriaceous in fruit ; lemmas 

 awnless. 



1. Sphenopholis obtusata (Michx.) Scribn. Rhodora 8: 142. 1906. 



Air a obtusata Michx. Fl. Bor. Amer. 1: 62. 1803. 



Eatonia obtusata A. Gray, Man. ed. 2. 558. 1856. 



A slender erect perennial with simple culms, linear blades, and shining 

 spikelike panicles 5 to 8 cm. long. 



Meadows and open woods, northeastern United States to southern Mexico; 

 also in the mountains of Santo Domingo (Oonstanza, Valle Nuevo). Origi- 

 nally described from southeastern United States. 



73. KOELEBIA Pers. 



Spikelets 2 to 4-flowered, glumes unequal, slightly shorter than the florets; 

 lemmas awned. 



1. Koeleria phleoides (Vill.) Pers. Syn. PL 1: 97. 1805. 



Festuca plileoides Vill. Fl. Delph. 7. 1785. 



A slender erect sparsely pilose annual 10 to 25 cm. tall, with lax flat blades 

 and dense spikes of delicately awned spikelets. 



A native of Europe; introduced in Bermuda. 



74. AVENA L. 



Spikelets large, 2 to 4-flowered ; glumes equal, many-nerved, papery, exceed- 

 ing the florets ; lemmas bider^tate, bearing a dorsal awn, the awn sometimes 

 rudimentary. 



Lemmas pubescent with long brown hairs 1. A. fatua. 



Lemmas glabrous or nearly so 2. A. sativa. 



1. Avena fatua L. Sp. PI. 80. 1753. Wild oat. 

 A rather stout annual with long flat blades and large open panicles of large 



nodding spikelets. 



A native of Europe, introduced in America, especially on the Pacific coast of 

 the United States. Collected in Jamaica (Hart 1493), no locality given. 



2. Avena sativa L. Sp. PI. 79. 1753. Cultivated oat. 

 Differs from the preceding in its glabrous florets, and in the awns wanting or 



reduced and readily disarticulating. 



Commonly cultivated in temperate regions and escaped or spontaneous in 

 fields and waste places. Occasionally spontaneous in the cooler parts of the 

 Tropics. Found in Cuba (nearHabana, Le6n 809) and Jamaica (near summit 

 of Blue Mountain Peak, Hitchcock 9369). 



75. DANTHONIA DC. 



Spikelets several-flowered ; glumes subequal, exceeding all the florets ; lemmas 

 bifid, with a twisted awn between the teeth; awn flat, formed by the extension 

 of the 3 middle nerves of the lemma. 



