208 University of California Publications in Botany. [VOL. 3 



80. DYSODIA Cav. 



Ours strong-scented perennial desert herbs with conspicu- 

 ously striate stems and rather large terminal heads. Herbage 

 either -glabrous or minutely pubescent but the involucres blotched 

 with large purple oil-glands. Involucre with an inner series of 

 nearly or quite distinct bracts and an outer series of much shorter 

 calyculate ones. Achenes cylindrical or angled, striate, glabrous 

 in our species. Pappus-paleae about 10, each resolved into numer- 

 ous capillary divisions. 



Leaves spinulose-dentate : involucre 12 to 15 mm. high 1. "D. Cooperi. 



Leaves 3 to 5-parted: involucre 10 to 12 mm. high 2. D. poroplvylloides. 



1. D. Cooperi Gray, Proc. Am. Acad. ix. 201 (1874). 



Plant 3 to 9 dm. high, with numerous erect stems (simple or 

 branched) from a more or less woody base: leaves alternate, 15 

 mm. or less long, broadly ovate or orbicular to lanceolate, spinu- 

 lose-dentate : principal bracts of the involucre 20 to 30, acumi- 

 nate: rays usually 8 to 12, orange-yellow (said to turn reddish). 

 1 cm. long. 



From the Mohave and Colorado deserts (Lower Sonoran 

 Zone) east into Arizona: Hesperia to Cushenberry Springs, Par- 

 ish, nos. 1257, 2392, 3721; Mohave River district, Palmer, no. 

 194; near Hesperia, May, 1901, Parish & Greata; near Barstow. 

 Hall, no. 6168 ; Mountain Springs, near the southern boundary of 

 Imperial Co., Parish, no. 2096; Providence Mts. and Warren's 

 Well, Brandegee; near Kingman, Arizona, Jun., 1893, Wilson. 



2. D. porophylloides Gray, Mem. Am. Acad. v. 322 (1855). 



Size and habit of the last preceding : lower leaves (some oppo- 

 site or even alternate) petioled, parted into cuneate to lanceolate 

 entire or incised divisions ; upper leaves reduced, entire and linear 

 or simply incised : principal bracts of the involucre 14 to 20, ab- 

 ruptly acute or mucronate: rays yellow, few and inconspicuous 

 or none. 



In the Lower Sonoran Zone from the western borders of the 

 Colorado Desert east into Arizona, south into Mexico : eastern 

 base of San Jacinto Mt., Parish, Hall, no. 2109 ; San Felipe. 

 Parish; near Dale, San Bernardino Co., Hall, no. 6038. 



