556 POACE.E. 



not webbed at the base, ovate, acute, 4 mm. long, the upper third 

 scarious; palea linear, 3.7 mm. long, scabrid on the keels. 



Mexico, Pringle 1437, Palmer 1316; New Mexico, Tracy. 



43. P. Orcuttiana Vasey, West. Am. Scientist in Aug. 1887. 



An erect perennial, about 60 cm. high. Leaves of the culm 3 in 

 number, sheaths smooth; ligule scarious, fringed, 5 mm. long; blades 

 of sterile shoots thin, flat, taper-pointed, 10-15 cm. long, the upper 

 blade of the culm 5-7 cm. long. Panicle purplish, 12-15 cm. 

 long, rays in fours and fives, the longest 8-9 cm. long, bearing about 

 25 sj^ikelets on the outer half. Spikelets linear, purplish, 6-8 mm. 

 long, 3-5-flowered, scaberulous; empty glumes thin, 3-nerved and 

 green only near the base, first 3 mm. long, second 3-4 mm. long; 

 floral glume thin, 3.4-4.5 mm, long, with a trace of a tuft of hairs 

 at the base, oval, subacute, apex often erose; palea about the length 

 of its glume, linear before spreading, 2-toothed, ciliolate on the 

 keels. Stamens 3. Anthers 2.5 mm. long. 



Lower California (northern part), Orcutt in 1886 for U. S. 

 Dept. AgricLil. 



127. (257). COLPODITJM Trin. Fund. Agrost. 119 (1820). Arc- 

 topMla Eupr. Beit. Pfl. Iluss. Eeich. 2: 62 (1845). 



Spikelets 1-2-flowered, rarely 3-flowered, rachilla articulate 

 above tlie lower glumes and between the florets. Empty glumes 

 awnless, softly membranous or hyaline, 1-3-nerved or destitute of 

 nerves, obtuse or rather acute, unequal; floral glume with the tex- 

 ture of the empty glumes, very broad, obtuse, more or less 5-nerved, 

 the lateral ones short or almost obsolete ; palea about as long as its 

 glume, hyaline, 2-nerved. Stamens 3. Styles short; distinct. 

 (Ji'ain oblong, without a groove, included, but not adherent. An- 

 nual or perennial grasses. Leaf-blades flat or almost setaceous. 

 Panicle slender, effuse, pyramidal, branches capillary. Spikelets 

 often small, sometimes colored. 



Ten species are known in A?;ia, Europe and North America. 

 The genus is very closely allied to Poa and by some made a section 

 of that genus. 



The spikelets are small, containing only one or two flowers, 

 thus connecting Poa with the Agrosteae. The Arctic plant pub- 



