688 conteibutiojSts feom the national heebaeium. 



Stems with, few erect branches, green; 

 heads less than 15 mm. broad; 

 leaves with numerous salient teeth. 10. M. centaureoides. 

 Stems with numerous, mostly spreading 

 branches; heads more than 15 mm. 

 broad; leaves with few, never 



salient teeth 11. M. bigelovii. 



Plants glandular only on the bracts, or also spar- 

 ingly on the peduncles, then only finely 

 glandular. 



Leaves linear, very acute, entire 12. M. angustifolia. 



Leaves oblong to obovate, toothed, mostly 

 obtuse. 

 Basal leaves rounded-spatulate, the cau- 

 line ones obovate, tapering to the 



base 13. M. ampli/olia. 



Basal leaves oblanceolate, acute, the 

 cauline ones oblong to elliptic or 

 lanceolate, not noticeably tapering 

 to the base 14. M. aquifolia. 



1. Machaeranthera tanacetifolia (H. B. K.) Nees, Gen. Sp. Aster. 224. 1832. 

 Aster tanacetifolius H. B. K. Nov. Gen. & Sp. 4: 95. 1820. 



. Dieteria coronopifolia Nutt. Trans. Amer. Phil. Soc. n. ser. 7: 302. 1841. 

 Machaeranthera coronopifolia A. Nels. Bot. Gaz. 37: 268. 1904. 

 Type locality: Mexico. 



Range: Wyoming and Nebraska to Arizona and western Texas and southward. 

 New Mexico : Throughout the State at lower altitudes. Sandy soil, in the Lower 

 and Upper Sonoran zones. 



2. Machaeranthera tagetina Greene, Pittonia 4: 71. 1899. 

 Machaeranthera tanacetifolia humilis A. Gray, PI. Wright. 2: 74. 1853. 

 Machaeranthera humilis Standley, Muhlenbergia 5: 48. 1909. 



Type locality: Arizona. 



Range : Southwestern New Mexico and southern Arizona. 



New Mexico: Near Ojo de Gavilan {Wright 1151). Lower Sonoran Zone. 



3. Machaeranthera pygmaea (A. Gray) W^oot. & Standi. Contr. U. S. Nat. Herb. 



16: 189. 1913. 

 Macheranthera tanacetifolia pygmaea A. Gray, PI. Wright. 2: 74. 1853. 

 Aster tanacetifolius pygmaeus A. Gray, Syn. Fl. 1^: 206. 1884. 



Type locality: "Dry, stony hills, valley of the Salado, Chihuahua, and near 

 El Paso." 



Range: Western Texas to southern Arizona and northern Mexico. 

 New Mexico: A single specimen seen, without definite locality. 



4. Machaeranthera parviflora A. Gray, PI. Wright. 1: 90. 1852. 

 Aster parvifloru^ A. Gray in Brewer & Wats. Bot. Calif. 1: 322. 1876. 

 Type locality: Along the Rio Grande, western Texas. 



Range: Western Texas to southern Arizona. 



New Mexico: Farmington; Cedar Hill; Albuquerque; Mesilla Valley; White 

 Sands; Alamogosdo. Sandy soil of plains, in the Lower and Upper Sonoran zones. 



5. Machaeranthera cichoriacea Greene, Leaflets 1: 148. 1905. 

 Type locality: Canyon of Deer Run, southern Colorado. 

 Range: Southern Colorado and northern New Mexico. 



New Mexico: Zuni; Shiprock; Carrizo Mountains; Cedar Hill; Farmington; Chama, 

 Dry plains, in the Upper Sonoran Zone. 



