( 480 ) 
Specimens examined: Signal Mountain, Abrams 3156, and Dec. 
29, 1907; McCoy wash, Colorado Desert, Hall 5930. 
4. Ewcenta Farinosa A. Gray; Torr. in Emory, Notes Mil. 
Reconnois. 143. 1848. 
Type locality: According to Emory’s notes (page 103) this 
species was collected in southern California in the vicinity of 
Carriso Creek. 
Distribution: San Bernardino Valley, southward to northern 
Lower California and eastward to Arizona. Lower Sonoran. 
Specimens examined: Vicinity of San Bernardino, Parish 4782; 
Signal Mountain, Abrams 3159; near Mentone, Abrams @ Me- 
Gregor 823. 
14. PICROTHAMNUS. 
1. PrcRorHaMNUS DESETORUM Nutt. Trans. Am. Phil. Soc. II. 7: 
Artemisia spinescens Eaton, Bot. King. ee ee pl. ro. 1871. 
Type locality: “North sources of the Platt 
Distribution: Mohave Desert of southern California extending 
northward throughout the Great Basin region. Upper Sonoran. 
Specimens examined: I have not seen any specimens within 
our range 
1s. ARTEMISIA. Sace-prusu. 
Heads heterogamous; marginal flowers pistillate, the central perfect; leaf- 
segments filiform. 1. a. californica. 
Heads homogamous; the flowers all perfect; leaf-segments not filiform. 
Achenes glabrous. 
Involucre oblong, 3-8, or rarely 9-flowered. 
Accessory bracts of the involucre short and ovate. 
2. A. tridentata. 
Accessory bracts of the involucre oblong or lanceolate. 
3. . tripartita. 
Involucre short-campanulate, 9—12-flowered; bracts all ovate or 
oval, glabrate. 4. A. Rothrockii. 
Achenes pubescent. 5. ad. Parishii. 
1. ARTEMISIA CALIFORNICA Less. Linnaea 6: 523. 1831. 
Artemisia abrotanoides Nutt. Trans. Am. Phil. Soc. II. 7: 399. 
1841. 
