GRIFFITHS THE GRAMA GRASSES. 421 



The species is distinct and characteristic, and there are none with which it may be 

 easily confused. Its general aspect is distinct and easily recognized, but the minuter 

 characteristics of the spikelets are most variable. The above description was drawn 

 from Griffiths 7071, which corresponds very imperfectly with the drawings of Griffiths 

 7261, published herewith, especially in the character of the rudiment. The latter 

 form is the variety aristosa, which it does not seem wise to recognize as a subspecies on 

 account of its extreme variation and the intergradations between it and the typical 

 form. - 



As would be expected in a plant of such wide distribution, there are great variations 

 in many if not all of the ordinary taxonomic characters. The accompanying text 

 figures show some of these in so far as they relate to the floral structures. As a rule, the 

 general plant body would be pronounced smooth, but often the leaves and sheaths are 

 quite densely papillose-hairy.. A specimen collected by Dr. Short in Kentucky 

 ("Knob of the Crab Orchard"), and another, MacDougal 273, Flagstaff, Arizona, both 

 show the development of this character. It frequently occurs that the leaves have 

 conspicuously serrate edges, or have regularly placed papillose hairs on the edges. 

 Shear 707, Osborne, Kansas, is a good example of the development of the latter char- 

 acter. A specimen collected by Eggert in Jefferson County, Missouri, August, 1891, 

 in the herbarium of the Missouri Botanical Garden, has pronounced papillose hairs on 

 the edges of the leaves and very wide spikes, but other plants of the same collection 

 have short spikes and look very peculiar for this species. A specimen in the same 

 herbarium, collected by Bush in McDonald County, Missouri, July 24, 1903, is espe- 

 cially hairy on both the leaves and the sheaths. This condition is to be distinguished 

 from that of the Eggert specimen above. The hairs are papillose also, but occur on 

 the lower side of the leaves and the upper portion of the sheaths. There is none of 

 this in the Eggert specimen. A specimen from Eggert in same herbarium from St. 

 Clair, Illinois, is very similar to the Bush plant. 



HERBARIUM SPECIMENS. 



Arizona: Blumer 1671, Chiricahua Mountains. Hitchcock 3497, Tucson; 3655, Pata- 

 gonia. Tidestrom 925, Jerome Junction. Nealley 1661, Monmouth, Rincon 

 Mountains. MacDougal 799, Dos Cabezos; 273, Flagstaff. Parish 318. Chase 

 5825, Indian Gardens, Grand Canyon. Griffiths 3373, Santa Rita Forest Reserve; 

 1438, Benson; 1837, Dragoon Mountains; 1907, Cochise. Holzner 1569, Huachuca 

 Mountains. Knowlton 1961, San Francisco Mountains. Davidson 306, Clifton. 

 Griffiths & Thornber 188 and 189, Santa Rita Mountains. Leiberg 5734, San Fran- 

 cisco Mountains. Jones 6066, Canaan Ranch. Mearns 859, 1065, south of 

 Bisbee; 1118, San Pedro River, Mexican Boundary. Zuch 30, Holbrook. 



California: Hall 2138, San Jacinto Mountains. 



Colorado: Chase 5310, Manitou; 5408, Las Animas County. Tidestrom 66, Hugo. 

 Clements (Herb. Form. Colo.) 2. Crandall 3541, Fort Collins. Hitchcock 1792, 

 Pikes Peak, Jones 548, Morrison. Tweedy 376, Durango. Griffiths 3311, Rocky 

 Ford. Shear 969, Canyon City; 948, Salida. Williams 2165 and 2120, Colorado 

 Springs. Baker, Earle & Tracy 970, Durango. 



Connecticut: Bissell, Housatonic River near Oxford. 



Illinois: Hill 181 in 1896, Will County. V. H. Chase, 1875, Princeville. Gleason 

 1001, Havana. McDonald 60, Peoria. Skeels 534, Joliet, Waite, Ogle County 

 in 1887. Wilcox 62, Manitou. 



Indiana: Dormer 58, Elston. 



Iowa: Fink 433, Fayette. .Morris A255, Murray to Thayer. Pommel & Cratty 756, 

 Ledyard. Bad 1008, Manchester. Pommel 645, Des Moines. 



