376 



COMPOSITAE. 



VOL. III. 



16. CHRYSOTHAMNUS Nutt. Trans. Am. Phil. Soc. (II) 7: 323. 1840. 



Low shrubs, with equably leafy branches, hard wood, linear leaves, and discoid heads 

 of yellow perfect flowers. Heads narrow, 5-7-flowered. Involucre oblong to narrowly 

 campanulate, its bracts more or less keeled, thin, or papery, impricated in several series, 

 often so as to form 5 vertical rows. Corolla 5-toothed. Anthers obtuse at the base. Style- 

 branches exserted, their appendages subulate to filiform. Achenes narrow, mostly pubescent. 

 Pappus of copious capillary roughened bristles. [Greek, golden-bush.] 



About 30 species, natives of western North America. Type species : Chrysothamnus pumilus Nutt. 



Heads about <6" high; involucral bracts obtuse or mucronulate. i. C. graveolens. 



Heads 7"-io" high; involucral bracts subulate-tipped. 2. C.Howardi. 



i. Chrysothamnus graveolens (Nutt.) 

 Greene. Fetid Rayless Golden- 

 rod. Fig. 4204. 



Chrysocoma graveolens Nutt. Gen. 2: 136. 



1818. 

 Bigelovia graveolens A. Gray, Proc. Am. Acad. 



8 : 644. 1873. 

 Chrysothamnus graveolens Greene, Erythea 3 : 



108. 1895. 



Sparingly tomentose above, or glabrate, 

 much branched, very leafy, i-4$ high, 

 odorous. Leaves linear, i'-3' long, i"-2" 

 wide ; heads 5"-6" high, very numerous and 

 crowded in terminal compound corymbose 

 cymes ; rays none ; involucre narrowly cam- 

 panulate, acute at the base, its bracts oblong 

 or linear-oblong, acute or acutish, imbri- 

 cated in about 4 series; achenes linear; 

 pappus-bristles soft, copious. 



In sterile, especially alkaline soil, Montana 

 to western Nebraska, Utah and New Mexico. 

 Included in our first edition in the C. nauseosa 

 (Pursh) Britton, a densely tomentose far 

 western species. Rabbit-brush. Aug.-Oct. 



2. Chrysothamnus Howard! (Parry) 

 Greene. Howard's Rayless Golden- 

 rod. Fig. 4205. 



Linosyris Howardi Parry ; A. Gray, Proc. Am. 

 Acad. 6 : 541. 1865. 



Bigelovia Howardi A. Gray, Proc. Am. Acad. 8 : 

 641. 1873. 



Chrysothamnus Howardi Greene, Erythea 3 : 113. 

 1895- 



Similar to the preceding species, white- 

 tomentose when young, glabrous or nearly so 

 when old, tufted, much branched, 6'-io' high. 

 Leaves narrowly linear, entire, i'-2' long, 

 about i" wide; heads 7"-io" long, narrow, 

 5-flowered, more or less glomerate, usually 

 surpassed by the upper leaves; rays none; 

 involucre slightly arachnoid-pubescent, its 

 bracts lanceolate, thin, acuminate or subulate- 

 tipped ; achenes nearly linear, pubescent. 



In dry soil, western Nebraska to Wyoming, 

 Colorado, Utah and New Mexico. July-Sept. 



