FLOWERING PLANTS AND FERNS OF ARIZONA 957 



westward, cultivated and escaping or becoming established elsewhere 

 throughout the United States. 



A sheet of Helianthus subrhomboideus Rydb., labeled "Arizona, Dr. E. Palmer, 

 1869," is in the U. S. National Herbarium. The species is not otherwise; known 

 from Arizona but is reported from New Mexico. As the data accompanying 

 Palmer's plants of 1869 are not always reliable, it seems best to await additional 

 material before formally including the species in the flora of Arizona. 



63. FLOURENSIA.™ Tarbush, varnishbush 



Resinous, much-branched shrub; leaves alternate, small, ovate to 

 oval, entire; heads rather small, discoid, yellow, nodding, axillary and 

 terminal; involucre herbaceous; achenes cuneate, laterally compressed 

 but somewhat thickened, villous; pappus of 2 unequal awns. 



1. Flourensia cernua DC, Prodr. 5: 593. 1836. 



Cochise County, 4,000 to 5,000 feet, plains and mesas, locally 

 abundant, July to December. Western Texas to southeastern Arizona 

 and northern Mexico. 



A small shrub with hoplike odor and bitter taste, unpalatable to 

 livestock. The leaves and heads are sold in the drug markets of 

 northern Mexico under the name "hojase" or "hojasen" and are 

 taken in the form of a decoction for indigestion. 



64. ENCELIA80 



Low, branching shrubs; leaves alternate, ovate or oblong, entire or 

 toothed; heads medium -sized, solitary or panicled, radiate or discoid, 

 yellow, or with the disk purple; rays neutral; achenes compressed, 

 very flat, obovate, notched at apex, ciliate, more or less pubescent 

 on the sides; pappus none, or of 1 or 2 weak awns. 



Key to the species 



1. Heads cymose or panicled; inflorescence glabrous or essentially so; leaves 

 densely whitish-tomentulose 1. E. farinosa. 



1. Heads solitary at the tips of the stem and branches; peduncles pubescent; 

 leaves not tomentulose 2 E. frutescens. 



1. Encelia farinosa A. Gray ex Torr. in Emory, Mil. Reconn. 143. 



1848. 



Mohave County to western Gila, Maricopa, Pinal, Pima, and 

 Yuma Counties, up to 3,000 feet, very abundant on dry rocky slopes, 

 November to May. Southern Nevada, southern and western Arizona, 

 southern California, and northwestern Mexico. 



The var. phenicodonta (Blake) I. M. Johnston, which has dark 

 purple instead of yellow disk flowers, occurs with the typical form in 

 the Mohawk and Tule Mountains, Yuma County. 



Brittlebush, incienso. The plants reach a height of about 1 m. 

 The stems exude a gum which was chewed by the Indians, and also 

 used as incense in the churches of Baja California. 



79 Reference: Blake, S. F. revision of the genus flourensia. Contrib. CJ. S. Natl. Herbarium 20: 



393-409. 1921. 



80 Reference: Blake. S. F. a revision of encelia and some allied geneka. Amor. Acad Arts and 



Sci. Proc. 49 (Gray Herbarium Contrib. 41): 358-376. 1913. 



