FLOWERING PLANTS AND FERXS OF ARIZONA 947 



7. Leaves slender-petiolecl, not spinous-toothed (8). 



8. Leaves broadly ovate, about as long as wide, 3-nerved, obtuse or 

 acutish, bluntly toothed, sometimes lobed; fruit mostly turbinate- 

 obovoid, 5 to 7 mm. long, bearing about 8 to 20 subulate hook- 

 tipped spines, these 1.5 to 2.5 mm. long, often flattish at base. 



7. F. CORDIFOLIA. 



8. Leaves elongate-triangular or oblong-lanceolate, pinnate-veined, acumi- 

 nate, coarsely toothed; fruit fusiform (Xanthium-like) , about 12 mm. 

 long, bearing very numerous slender-subulate hook-tipped spines, 

 these 2 to 3 mm. long, not flattened at base. 8. F. ambrosioides. 



1. Franseria confertiflora (DC.) Rvdb., North Amer. Fl. 33: 28. 



1922. 



Ambrosia conjert'i flora DC, Prodr. 5: 526. 1836. 



Franseria tenuifolia Harv. and Grav in A. Gray, Amer. Acad. 



Arts and Sci. Mem. ser. 2, 4: 80." 1849. 

 Franseria incana Rydb., North Amer. FL 33: 30. 1922. 



Near Flagstaff (Coconino County) and Kingman (Mohave County) 

 to Cochise, Santa Cruz, and Pima Counties, 1,000 to 3,500 feet, 

 mesas and slopes, sometimes a weed in cultivated land, April to Oc- 

 tober, type of F. incana from near Fort Huachuca (Wucox in 1892). 

 Oklahoma and Colorado to California, south to northern Mexico. 



2. Franseria acanthicarpa (Hook.) Coville, Contrib. U. S. Natl. 



Herbarium 4: 129. 1893. 



Ambrosia acanthicarpa Hook., Fl. Bor. Amer. 1: 309. 1834. 

 Gaertneria acanthicarpa Britton, Torre v Bot. Club Mem. 5: 

 332. 1894. 



Apache, Navajo, and eastern Coconino Counties, 4,500 to 5,500 

 feet, dry or moist sandy soil, June to December. Minnesota to 

 Alberta, south to western Texas, northern Arizona, and California. 



Affords forage for sheep in northern Arizona. 



3. Franseria discolor Nutt., Amer. Phil. Soc. Trans, ser. 2, 7: 345. 



1840. 

 Near the San Francisco Peaks and Flagstaff, Coconino County, 

 6,200 to 7,000 feet (Leiberg 5918, Whiting 756), plains and cultivated 

 ground, June to September. Nebraska to Wyoming, south to New 

 Mexico and Arizona. 



4. Franseria dumosa A. Grav in Frem., Exped. Rocky Mount. 



Rpt. 316. 1845. 



Franseria albicaulis Torr., PI. Fremont. 16. 1853. 



Mohave County to western Pinal and Pima Counties and through- 

 out Yuma Count}*, up to 3,000 feet, very common on dry plains and 

 mesas, April to November. Southern Utah to southeastern California 

 and northwestern Mexico. 



White bur-sage. Plants up to 1 m. high, much branched, compact, 

 spinescent. This plant is said to be preferred for forage by horses 

 to all other desert shrubs. It is sometimes called burroweed, a 

 name used for various southwestern plants. 



5. Franseria eriocentra A. Grav, Amer. Acad. Arts and Sci. Proc. 



7: 355. 1868. 



Grand Canyon (Coconino County) and Beaver Dam (Mohave 

 County) to western Gila, Maricopa', and Pinal Counties, 1,500 to 



