46 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Fig. 27.— Distribution of P. arizonicum. 



DISTRIBUTION. 



Open sandy or stony ground, western Texas to southern California and northern 

 Mexico. 



Texas: El Paso, Jones in 1884; Presidio County, Nealley in 1892. 



New Mexico: Mangas, Smith in 



1896, Metcalfe in 1897; Las 

 Cruces, Griffiths 7399 in part; 

 Mogollon Mountains, Metcalfe 

 768; Sierra County, Metcalfe 

 1294. 



Arizona : Tucson Mountains, Grif- 

 fiths 6152, 6938, 6939; Tucson, 

 Griffiths 1596, 3356, 6168, 6737, 

 7017, Hitchcock 3482; Santa 

 Rita Mountains, Griffiths 5981, 

 6894, 6990, Griffiths & Thornber 

 75, 230, 239; Santa Catalina 

 Mountains, Griffiths 7143, 7148, Lemmon 3062; Sasabe, Griffiths 6929; Bowie, 

 Tourney in 1896; Lowell, Pringle 465; Mescal, Griffiths 1810; Fort Huachuca, 

 Wilcox in 1894; Patagonia, Hitchcock 3695; Bisbee, Mearns 1072; San Pedro 

 River, Merton 1694; Cochise, Griffiths 1913; without locality, Lemmon 353. 



California: Jamacha, Canby 8 in 1894. 



Mexico : San Jose del Cabo, Brandegee 18 in 1890; south of Nogales, Hitchcock 3637 ; 

 Arroyo San Lazaro, Brandegee in 1902 ; Guaymas, Hitchcock 3562, Palmer 159 in 

 1887 in part; Hermosillo, Hitchcock 3542; Nogales, Griffiths 6747, 6759; Loquka, 

 [Lacuca?] Sonora, Griffiths 6891; Topolobampo, Palmer 250 in 1897; State of 

 Chihuahua, Palmer 1 b in 1885, Pringle 487; State of Durango, Rose 2280. 



15. Panicum texanum Buckl. 



Panicum texanum Buckl . Prel. Rep. Geol. Agr. Surv. Tex. App. 3. 1866. "Austin, 

 Texas. " The type specimen, in the herbarium of the Philadelphia Academy, consists 

 of two overmature plants lacking the base. 



DESCRIPTION. 



Plants erect or ascending, often decumbent and rooting at the lower nodes, branching 



from the base and com- 

 monly from the lower 

 and middle nodes; culms 

 stout, 50 to 150 cm. high, 

 or in robust specimens as 

 much as 3 meters high, 

 softly pubescent at least 

 below the nodes and be- 

 low the panicles; sheaths 

 softly pubescent, often 

 papillose; densely ciliate, 

 the lower shorter than the 

 internodes, the upper usu- 

 ally overlapping; ligules 

 about 1 mm. long; blades 

 ascending or spreading, 8 

 to 20 cm. long, 7 to 15mm. 

 wide, rounded at the base, 

 softly pubescent on both 

 panicles finally exserted, 8 to 20 cm. long, 1 to 3 cm. 



Fig. 28.— P. texanum. From type specimen 



surfaces, often finely papillose, 



