FLOWERING PLANTS AND FERNS OF ARIZONA 159 



4. Cyperus acuminatus Torr. and Hook., Ann. Lye. N. Y. 3: 435. 1836. 

 Graham, Gila, Cochise, and Pima Counties, 5,000 feet or lower. 



Illinois to North Dakota, Florida, Arizona, and California. 



The form occurring in Arizona is var. cyrtolepis (Torr. and Hook.) 

 Kukenthal (C. cyrtolepis Torr. and Hook.) with taller stems, less com- 

 pact inflorescence, and broader spikelets and scales than in typical 

 C. acuminatus. 



5. Cyperus difformis L., Centuria PL II. 6. 1756; Amoen. Acad. 4: 



302. 1760. 



Cyperus lateriflorus Torr., U. S. and Alex. Bound. Bot. 226. 1859. 



Not known definitely to occur in Arizona but has been collected at 

 Santa Cruz, Sonora, about 10 miles south of the international boundary 

 (Wright 1950, the type of C. lateriflorus). Mexico; tropical and sub- 

 tropical regions of the Old World. 



6. Cyperus amabilis Yahl, Enum. PL 2: 318. 1806. 



Sonoita Valley and foothills of the Patagonia Mountains, Santa 

 Cruz County, 4,000 to 6,000 feet (Rothrock 599, Harrison and Peebles 

 4733). Widely distributed in the tropical and subtropical parts of 

 America; Eastern Hemisphere. 



7. Cyperus seslerioides H. B. K., Nov. Gen. et Sp. 1: 209. 1816. 

 Huachuca Mountains, Cochise County (Wilcox 361, Epling and 



Stewart in 1936), Sonoita Valley, Santa Cruz County, 6,500 feet 

 (Rothrock 614). Texas and southern Arizona to northern South 

 America. 



8. Cyperus laevigatus L., Mant. 179. 1771. 



San Bernardino Ranch, Cochise County, 4,000 feet (Mearns 820). 

 Texas, southern Arizona, southern California, Mexico, and Tropics of 

 both the Eastern and the Western Hemispheres. 



An imperfect specimen collected at Quitobaquito, Pima County 

 (Mearns 2785), is probably of this species. 



9. Cyperus niger Ruiz and Pavon, Fl. Peruv. Chil. 1: 47. 1798. 



Cyperus melanostachys H. B. K., Nov. Gen. et Sp. 1: 207. 1816. 



McNary (Apache County), Rye Creek (Gila County), and moun- 

 tains of Cochise and Santa Cruz Counties, 3,500 to 7,500 feet. Texas 

 to California and southward to South America. 



The forms occurring in Arizona are var. castaneus (S. Wats.) Kuken- 

 thal and var. robustus (Liebm.) Kukenthal. 



10. Cyperus albomarginatus Mart. andSchrad. ex Nees in Mart., Fl. 



Bras. 2 l : 9. 1842. 



Cyperus flavicomus Vahl, Enum. PL 2: 360. 1806. Not Michx. 

 1803. 



Near Ruby, Santa Cruz County, 3,600 to 4,300 feet (Kearney and 

 Peebles 13785, 14480). Virginia to Florida west to southern Arizona, 

 and southward; widely distributed in tropical and subtropical parts of 

 both the Eastern and the Western Hemispheres. 



286744° — 42 11 





