FLOWERING PLANTS AND FERNS OF ARIZONA 141 



4. Phalaris caroliniana Walt., Fl. Carol. 74. 1788. 



Yavapai, Gila, Pinal, Maricopa, and Pima Counties, 1,000 to 6,000 

 feet, moist ground, April to August. Virginia to Colorado, south to 

 Florida and Texas, west to Arizona, California, and Oregon. 



5. Phalaris angusta Nees in Trim, Gram. Icon. 1: pi. 78. 1827. 

 Sacaton, Pinal County (Harrison 5266). Open ground at low alti- 

 tudes, Mississippi, Louisiana, Texas, Arizona, and California; southern 

 South America. 



62. LEERSIA. Cutgrass 



Slender, erect or decumbent perennial with creeping rhizomes and 

 flat, scabrous leaf blades; spikelets 1 -flowered, laterally compressed, 

 disarticulating from the pedicel; glumes wanting; lemma chartaceous, 

 boat-shaped, hispid; palea as long as the lemma but much narrower, 

 the margins firmly held by the margins of the lemma. 



1. Leersia oryzoides (L.) Swartz, Prodr. Veg. Ind. Occ. 21. 1788. 



Phalaris oryzoides L., Sp. PL 55. 1753. 



Greenlee and Pima Counties, a weed along irrigation ditches. 

 Quebec and Maine to eastern Washington, south to northern Florida, 

 Arizona, and southern California; Europe. 



63. TRICHACHNE. Cottontop 



Perennial, with flat leaf blades and slender, erect or ascending 

 racemes forming a white silky inflorescence ; first glume minute ; second 

 glume and sterile lemma equal, covering the fruit, conspicuously 

 villous with long hairs; fertile lemma acuminate, brown. 



1. Trichachne calif ornica (Benth.) Chase, Wash. Acad. Sci. Jour. 23: 

 455. 1933. 



Panicum calijornicum Benth., Bot. Voy. Sulph. 55. 1840. 

 Valota saccharata (Buckl.) Chase, Biol. Soc. Wash. Proc. 19: 

 188. 1906. 



Mohave County to Cochise, Santa Cruz, Pima, and Yuma Counties, 

 1,000 to 6,000 feet, mesas and rocky hills in open ground. Texas to 

 Colorado, Arizona, and Mexico. 



Cottontop furnishes a considerable quantity of palatable forage for 

 a short period following spring or summer rain. 



64. DIGITARIA. Crabgrass 



Decumbent spreading annual with flat leaf blades and rather slender, 

 ascending or spreading, digitate racemes; spikelets usually in pairs on 

 one side of a flat, winged rachis; first glume evident ; second glume 

 shorter than the sterile lemma, exposing the fruit, more or less 

 pubescent; fertile lemma cartilaginous, pale, with hyaline margins. 



1. Digitaria sanguinalis (L) Scop., Fl. Cam. ed. 2, 1: 52. 1772. 



Panicum sangu in ah L., Sp. PI. 57. 1753. 



Syntherisma sanguinalis Dulac, Fl. Ilaut. Pyr. 77. 1867. 



Sacaton (Pinal County) and western base of Patagonia Mountains 

 (Santa Cruz County). A common weed in waste places in temperate 

 and tropical regions of the world. 



