o46 POACE^L 



interrupted, 5-20 cm. long, rays in pairs, the longest 3-4 cm. long, 

 densely flowered on the upper half; in a very long panicle, the 

 lowest rays 5-7 cm. from the next above. Spikelets oval or ovate- 

 lanceolate, 3-6-flowered, 5-7 mm. long, joint of rachilla 0.7 mm. 

 long; empty glumes 3-nerved, first ovate-lanceolate, 2.5-3.5 mm. 

 long, second oval-lanceolate, 3-4 mm. long; floral glume oval, acute 

 or obtuse, notched at the apex, 3-3.5 mm. long, the nerve on each 

 side next the midnerve obscure, webby hairs at base often 4 mm. 

 long, hairs on the keel for three-fourths of its length and half the 

 length of tlie glume on the lateral nerves, 0.7 mm. long; palea 

 lanceolate, 2.7 mm. long, pubescent on the keels. Certainly a good 

 species. 



Texas, Curtiss 3477a from Eeverclion, Fendler 93 ; New Mexico, 

 Vasey for XJ. S. Dept. Agricul. 635; Arizona (Santa Catalina 

 Mountains), Pringh 458. 



Texas to Arizona. 



27. P. COMPRESSA L. Sp. PI. 69 (1753). Plat-stemmed Poa. 

 Blue Grass. Wire-grass. P. cDwepa Presl, Cyp. & Gram. Sic. 

 43 (1826). P. complanata Sclmr, Enum. PI. Transs. 770 (1866). 

 P. Langeana Reichb. Fl. Germ. Excurs. 140* (1833). P. onuralis 

 AYibel, Prim. Fl. "Worth. 114. P. polynQda Parn. Grass. Scotl. 

 84 (1842). P. suhcompressa Parn. 1. c. 



Glaucous, bluish gi'een, culms 30-60 cm. high, smooth, firm, 

 much compressed, ascending from cree^^ing rootstocks. Sheatlis 

 mostly much shorter than the internodes, ligule obtuse, about 1 

 mm. long; sterile shoots few, those of the culm 4, blades flat or 

 conduplicate, 4-10 cm. long, 3-4 mm. wide, the aj^ex abruptly 

 j)oiuted as in P. annua. Panicle usually contracted, linear or open 

 and ovoid, secund, 5-10 cm. long, lower rays scabrous, in i)airs or 

 single, the middle ones in threes or fours, the longest 3-4 cm. long, 

 flower-bearing on the outer half. Spikelets subsessile, oval or ovate- 

 lanceolate, 3-10-flowered, 4-6 mm. long, bluish green, often tinged 

 with purple, joint of rachilla 0.5 mm. long; empty glumes sub- 

 equal, 3-nerved, acute, ovate or elliptical-lanceolate, second 2.5-3 

 mm. long; floral glume 2.5-3 mm. long, firm, smootli or scabrid, 

 webby hairs few or wanting, pubescent on the keel and lateral 



