GRASS FAMILY 



173 



2. Danthonia thermale Scribn. 

 Northern Wild Oat-grass. Fig. 391. 



Danthonia spicata f^i)ictoniin Piper, Erythea 7: 103. 1899. 



Danthonia thermale Scribn. U. S. Dept. Agr. Div. Agrost. Circ. 



30: 5. 1901. 

 Merathrefta pinetorum Piper, Contr. U. S. Nat. Herb. 11: 122. 



1906. 



Culms tufted, erect, stouter than in D. intenncdia, 

 30-60 cm. tall ; blades flat, more or less pilose, 2-4 mm. 

 wide, the upper much reduced; inflorescence as in D. 

 intermedia; spikelets about 1 cm. long ; lemma sparsely 

 villous on the back, the callus short and scarcely pilose. 



Moist slopes in the Transition Zone; British Columbia to 

 Wyoming, south to Oregon. July-Aug. Type locality: Yellow- 

 stone Park. 



3. Danthonia unispicata ]\liinro. 



Few-flowered Wild Oat-grass. 



Fig. 



392. 



Danthonia unispicata Munro; Thurb. in S. Wats. Bot. Calif. 2: 

 294. 1880. 



Danthonia calif ornica unispicata Munro; S. Wats. Bot. Calif. 2: 

 294. 1880. 



Mcrathrepta unispicata Piper, Contr. U. S. Xat. Herb. 11: 123. 

 1906. 



Culms short, 15-20 cm. tall, about as long as the 

 numerous basal leaves; sheaths and blades pilose; 

 panicle reduced to a single spikelet, (often an abortive 

 spikelet, rarely a perfect one below) the pedicel about 

 12 mm. long, flexuous, pubescent above ; spikelets about 

 as in D. americana, the lemma more gradually acumin- 

 ate into awns. 



Rocky hills in the Arid Transition Zone; Washington to 

 California and Wyoming. May-Jyly. Type locality: California. 



4. Danthonia americana Scribn. 

 American Wild Oat-grass. Fig. 393. 



Danthonia grandiflora Phil. Anal. Univ. Chile 48: 568. 1873, not 



Hochst. 1851. sV 



Danthonia americana Scribn. U. S. Dept. Agr. Div. Agrost. Circ. 

 30: 5. 1901. 



Merathrepta americana Piper, Contr. U. S. Nat. Herb. 11: 123. 

 1906. 



Culms 30-60 cm. tall, smooth, tending to disarticulate 

 at the nodes ; sheaths pilose ; blades short, flat, or those 

 of the innovations involute; panicle bearing 2-5 spike- 

 lets, the pedicels usually about 12 mm. long, spreading or 

 somewhat reflexed ; glumes 12-18 mm. long, smooth, 

 acuminate, about 7-nerved ; lemmas 5-7 mm. long, smooth 

 and convex on the back, pilose at base and margins, broad, 

 abruptly contracted into 2 teeth with awns 2-6 mm. long, 

 the dorsal awn from between these teeth, geniculate, flat 

 and twisted below, straight and divergent above, exserted. 

 This and the other species have at the base of the sheath* 

 cleistogenes (hidden spikelets) with 1 or 2 larger florets 

 than those of the normal spikelets. 



Wet meadows and moist places in rocks in the Transition Zone; 

 British Columbia to Wyoming, south to the San Bernardino Moun- 

 tains; also in Chile. June-July. Type locality: Chile. 



