140 BULLETIN 772, IT. S. DEPARTMENT OF AGRICULTURE. 



64. PHLEUM L. 



Spikelets 1-flowered, laterally compressed, disarticulating above 



the glumes ; glumes equal, 

 membranaceous, keeled, 

 abruptly mucronate or 

 awned ; lemma shorter 

 than the glumes, hyaline, 

 broadly truncate, 3 to 5 

 nerved; palea narrow, 

 nearly as long as the 

 lemma. 



Annuals or perennials, 

 with erect culms, flat 

 blades, and dense, cylin- 

 dric panicles. About 10 

 species, in the temperate 

 regions of both hemi- 

 spheres. 



Type species : Phleum pra- 

 tense L. 



Phleum L., Sp. PI. 59, 1753 ; 

 Gen. PI., ed. 5, 29. 1754. 

 Four species are described, 

 P. pratense, P. alpinum, P. 

 arenarium, and P. schoe- 

 noides. The first species 

 is chosen as the type because 

 it is the only cultivated spe- 

 cies in the genus. The first 

 three species are still re- 

 tained in Phleum ; the fourth 

 is referred to Heleochloa. 



Stelephuras Adans., Fam. 

 PI. 2: 31. 607. 1763. Based 

 on Phleum L. 



Four species of Phleum 

 are found in the United 

 States. Our only native 

 species is P. alpinum L., 

 mountain timothy, a per- 

 ennial with short spikes, 

 two or three times as 

 long as wide, found in 

 the northern regions of 

 Eurasia and America and 

 extending south in the 

 mountains of Xew Eng- 

 land, in the Rocky Moun- 

 tains to Mexico, and in 

 the Sierra Nevada and 

 Coast Ranges to the San 



FIG. 77. Timothy, Phleum pratense. Plant, X i I T . ,.- . 



spikelet and floret, X 5. JaCintO Mountains. 



