STANDLEY TREES AND SHRUBS OF MEXICO 1485 



Heads thicker, turbinate to subglobose-turbinate, 1.5 to 3.5 mm. thick; 

 ray flowers 3 to 12, disk flowers 2 to 12. 

 Leaves (at least the lower) linear-spatulate, 1 to 2.5 mm. wide. 



4. G. argyrocarpa. 

 Leaves strictly linear or linear-filiform, 1.5 mm. wide or less. 



Heads subglobose-turbinate; flowers of ray and disk each 7 to 12; phyl- 

 laries with conspicuous broad and short herbaceous tips. 



5. G. californica. 

 Heads turbinate; flowers of ray and disk each 3 to 8; phyliaries with 



narrower and more obscure herbaceous tips 6. G. sarothrae. 



Involucre 5 to 6 mm. high; leaves linear-spatulate or linear-oblanceolate, 2 to 

 6 mm. wide 7. G. grandis. 



1. Gutierrezia lucida Greene, Fl. Franc. 361. 1897. 

 Xanthocephalum lucidum Greene, Pittonia 2: 282. 1892. 

 Gutierrezia glomerella Greene, Pittonia 4: 54. 1899. 



Chihuahua (?) and Coahuila to Zacatecas. Colorado to Texas, Arizona, and 

 California; type from Mohave Desert, California. 



Suffruticose, up to 60 cm. high; leaves linear-filiform to narrowly linear- 

 oblanceolate, 2 to 5.5 cm. long, 2.5 mm. wide or less, sparsely scabridulous; 

 heads fasciculate-cymose-panicled, 2.5 to 4.5 mm. long, about 1 mm. thick. 



2. Gutierrezia digyna Blake, Contr. U. S. Nat. Herb. 22: 59. 1924. 

 Known only from the type locality, San Luis Mountains, Sonera (?), along 



Arizona boundary' line. 



Suffrutescent, about 30 cm. high; lower leaves oblanceolate or spatulate-linear, 

 1.7 to 3.5 cm. long, 3 to 4.5 mm. wide, the upper linear or very narrowly spatulate- 

 linear; heads corymbosely cymose-panicled. 



3. Gutierrezia microcephala (DC.) A. Gray, Mem. Amer. Acad. n. ser. 4: 74. 



1849. 



Brachyris microcephala DC. Prodr. 5: 313. 1836. 



IGutierrezia haenkei Schultz Bip. Flora 38: 115. 1855. 



Gutierrezia euthamiae microcephala A. Gray, Syn. Fl. 1^ : 115. 1884. 



Gutierrezia filifolia Greene, Pittonia 4: 55. 1899. 



Chihuahua and Coahuila; type from Saltillo, Coahuila. Idaho to Arizona. 



Suffruticose, about 35 cm. high, hirtellous, corymbosely branched above; 

 leaves linear-filiform, 3 cm. long, 1 mm. wide or less; heads often pediceled, about 

 3.5 mm. high; phyliaries with rather conspicuous narrow greenish tips. 



4. Gutierrezia argyrocarpa Greenm. Proc. Amer. Acad. 40: 35. 1904. 

 Known only from the type locality, chalk bluffs of Tula, Hidalgo. 

 Suffruticose, hirtellous, about 30 cm. high; leaves linear-spatulate or the upper 



linear, 1 to 1.5 cm. long, scabridulous on margin; heads turbinate, about 3.5 mm. 

 high and 2.5 mm. thick, mostly pediceled, cymose-panicled; rays 5 or 6; disk 

 flowers 8 to 12. 



5. Gutierrezia californica (DC.) Torr. & Gray, Fl. N. Amer. 2: 193. 1842. 

 Brachyris californica DC. Prodr. 5: 313. 1836. 



Chihuahua. California and Arizona; type from California. 



Suffrutescent, the stem glabrous to hirtellous; heads rather few, usually not 

 glomerate, about as thick as long; phyliaries conspicuously green-tipped; ray 

 and disk flowers each 7 to 12. 



6. Gutierrezia sarothrae (Pursh) Britt. & Rusby, Trans. N. Y. Acad. 7: 10. 



1887. 

 Solidago sarothrae Pursh, Fl. Amer. Sept. 540. 1814. 

 Brachyris euthamiae Nutt. Gen. PI. 2: 163. 1818. 

 Gutierrezia euthamiae Torr. & Gray, Fl. N. Amer. 2: 193. 1842. 



