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 henrisphere. Originally described from Lapland. In the 
West Indies only at high altitudes in Santo Domingo (Constanza, Tiirckheim 
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. 
Aira 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 (Constanza, Valle Nuevo), Origi- 
nally described from southeastern United States. 
73. KOELERIA Pers. 
Spikelets 2 to 4-flowered, glumes unequal, slightly shorter than the florets; 
lemmas awned. 
1. Koeleria phleoides (Vill.) Pers. Syn. Pl. 1: 97. 1806. 
Festuca phleoides 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 bidentate, 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. Pl. 80. 1753. WIDLb 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. Pl. 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 (near Habana, Ledn 809) and Jamaica (near summit 
of Blue Mountain Peak, Hitchcock 2369). 
75. DANTHONIA DC. 
Spikelets several-flowered ; glumes subequal, exceeding all the florets ; 4emmas 
bifid, with a twisted awn between the teeth; awn flat, formed by the extension 
of the 3 middle nerves of the lemma. 
