72 CONTEIBUTIONS FEOM THE NATIONAL HEEBAEIUM. 



18. Muhlenbergia virescens (H. B. K.) Kunth, Rev. Gram. 1: 64. 1829. 

 Podosaemum virescens H. B. K. Nov. Gen. & Sp. 1: 132. 1816. 



Type locality: "Crescit locis asperis, excelsis legni Mexican! props Santa Rosa 

 de la Sierra et Puerto de Varientos, alt. 1350 hexap." 



Range: Arizona and New Mexico to Mexico. 



New Mexico: Northwestern New Mexico (Palmer); Ben More (Bigelow). Moun- 

 tains, in the Transition Zone. 



19. Muhlenbergia affinis Trin. M^m. Acad. St. Petersb. VI. 6^: 301. 1845. 

 Muhlenbcrgia vutcalfi Jones, Contr. West. Bot. 14: 12. 1912. 



Type locality: "Toluco," Mexico. 



Range: Southern New Mexico and Arizona and southward. 



New Mexico: Santa Rita Mountain; Fort Bayard; Filmore Canyon; Mangas 

 Springs; near Silver City. Dry hills, in the Upper Sonoran Zone. 



The type of M. vietcalfi {metcalfei?) is Metcalfe's 1485, from Santa Rita Mountain. 



20. Muhlenbergia subalpina Vasey, Descr. Cat. Grasses U. S. 40. 1885. 

 MuJiUnhergia gracilis breviaristata Vasey in WTieeler, Rep. U. S. Siuv. 100th Merid. 



6: 284. 1874. 

 Type locality: Twin Lakes, Colorado. 

 Range: Wyoming to New Mexico. 



New Mexico: Northern New Mexico (George Fasey). Mountains, in the Transition 

 Zone. 



21. MuMenbergia acuminata Vasey, Bot. Gaz. 11: 337. 1886. 



Type locality: "New Mexico." Type collected by Wright (no. 1993). 

 Range: Western Texas to Arizona. 



New Mexico : Kingston ; Mangas Springs; Filmore Canyon. Dry hills, in the Upper 

 Sonoran Zone. 



22. Muhlenbergia monticola Buckl. Proc. Acad. Phila. 1862: 91. 1863. 

 Mulilenhergia neomexicana Vasey, Bot. Gaz. 11: 337. 1886. 

 MuMenbergia jmnglei Scribn. Trans. N. Y. Acad. 14: 25. 1894. 



Type locality: "Northwestern Texas." 



Range : Western Texas to Arizona and Mexico. 



New Mexico: Santa Fe and Las Vegas mountains; Albuquerque; Watrous; Grant; 

 Mangas Springs; Kingston; Reserve; Dog Spring; Socorro; Organ Mountains; Dona 

 Ana Mountains; ^\Tiite Mountains. Dry slopes, in the Upper Sonoran Zone. 



The type of M. neomexicana was collected in New Mexico. 



27. ORYZOPSIS Michx. 



Slender perennials Avith flat or involute leaves and loosely flowered, spreading or 

 narrow panicles; spikelets 1-flowered, hermaphrodite; rachilla jointed above the 

 glumes and not produced behind the palea, usually extended below the lemma 

 into a short obtuse callus; glumes nearly equal, obtuse or acuminate; lemma a little 

 shorter than the glumes, rather broad, cartilaginous, terminated by a slender deciduous 

 awn; grain free. 



KEY to the species. 



Lemmas covered vnth long silky hairs, these much exceeding them 



in length 1. 0. hymenioides. 



Lemmas glabrf)us or short-pubescent. 



Leaves slender, involute; spikelets small, 2.5 to 4 mm. long. . 2. 0. micrantha. 



Leaves broad and flat; spikelets large, 6 to 8 mm. long 3. 0. asjierijotia. 



