198 GENUS CHRYSOTHAMNUS. 



ECOLOGY AND USES. 

 Chrysothamnus pyramidatus has not been seen in the field, and nothing is known of 

 its ecology and uses. 



11. CHRYSOTHAMNUS PARRYI (Gray) Greene, Erythea 3:113, 1895. Plates 30 to 32. 



Shrub 6 dm. or less high, the numerous branches erect or ascending, or widely spread- 

 ing in dwarf forms; bark of main stems fibrous, brown; twigs flexible, ascending, moder- 

 ately leafy, closely covered with a white or rarely greenish pannose tomentum, this 

 deciduous only near the base, the bark then brown; leaves narrowly to broadly linear 

 or linear-spatulate, acute or at least mucronate, 1 to 8 cm. long, 0.5 to 8 mm. wide, 

 1 -nerved, sometimes with 2 additional nerves, green and viscid-glandular or gray and 

 tomentulose; heads in leafy terminal racemes, these sometimes branching and sub- 

 paniculate; involucre 10 to 14 mm. high; bracts 10 to 20, in more or less obvious vertical 

 ranks, 1 -nerved, lanceolate, acuminate, chartaceous, the outer ones often with a slender 

 herbaceous tip, loosely puberulent at least on the margins; flowers 4 to 20; corolla tubular- 

 funnelform, 8 to 11 mm. long, either pubescent or glabrous; lobes 0.5 to 2.5 mm. long, 

 erect, glabrous or sparsely long-hairy; anther-tips linear-lanceolate and acute or linear 

 and somewhat obtuse (at least in subspecies nevadensis) , 0.5 to 0.8 mm. long; style- 

 branches long-exserted, the subulate appendage much exceeding the stigmatic portion; 

 achenes tapering slightly to the base, 4-angled, 5 to 6 mm. long when mature, densely 

 appressed-villous; pappus equaling or slightly exceeding the corolla, very soft, dull 

 white changing to tawny. {Linosyris parryi Gray, Proc. Acad. Phila. for 1863:66, 1863.) 



Mountains and foothills of western North America: Wyoming to western Nebraska, 

 New Mexico, California, and Utah. 



SUBSPECIES. 



Key to the Subspecies oj Chrysothamnus parryi. 

 Flowers 8 to 20 in each head, or only 5 to 7 in latior but the leaves then 4 ram. or more 

 wide; leaves lanceolate or oblanceolate to broadly linear. 

 Leaves 2.5 to 8 cm. long; plant 3 dm. or more high, the branches mostly erect. 



Flowers mostly 10 to 20 in the head; leaves mostly L5 to 3 ram. wide. Rocky 



Mountains (a) typicus (p. 198). 



Flowers mostly 5 to 11 in the head; leaves mostly 4 to 8 mm. wide, California. 



Involucre 9 to 10 ram. high; leaves thick and rigid; inflorescence congested. (6) holanderi (p. 199). 

 Involucre 12 to 14 mm. high; leaves thinner, soft; inflorescence elongated. . (c) latior (p. 199). 

 Leaves 1.0 to 1.5 cm. long; plant about 1 dm. high, the branches spreading at base. 



Southern California (d) imulus (p. 200). 



Flowers 5 to 7 in the head, or up to 10 in asper (the leaves then resinous-scabrid) ; leaves 

 narrowly linear except in some forms of asper. 

 Bracts of the involucre 8 to 12, not strongly keeled and the vertical rows rather 

 obscure. 

 Racemes several- to many-headed; foliage green, viscidulous, not tomentose or 

 only sparsely so. 



Resin-giands of the leaves short-stalked, prominent (e) asper (p. 200). 



Resin-glands of the leaves se.ssile, obscure (fj vulcanicus (p. 200). 



Racemes reduced to 1 or 2 heads each; foliage gray, tomentulose (g) morwcephalus (p. 200). 



Bracts of the involucre 13 to 20, rarely only 11 or 12 (or even fewer in howardi, 

 which may be recognized by the elongated upper leaves), more 

 strongly keeled, the vertical rows fairly obvious. 

 Uppermost leaves elongated, some of them overtopping the inflorescence; foliage 



gray-tomentulose; flowers pale yellow. Rocky Mountains (h) howardi (p. 201). 



Uppermost leaves seldom overtopping the inflorescence; foliage variously 

 pubescent; flowers clear yellow. 

 Bracts of the involucre with very slender straight tips. Rocky Mountains, (t) atlenuatua (p. 201). 

 Bracts of the involucre with slender tips at least some of which are spread- 

 ing or recurved. Nevada and California (j) nevadensis (p. 201). 



11a. Chrysothamnus parryi typicus. — Plant 3 dm. or more high; stems mostly 

 erect; leaves broadly linear, 3 to 8 cm. long, 1.5 to 3 mm. wide, 3-nerved, but only one 

 nerve prorninent, green, glabrous or microscopically puberulent and often obscurely resin- 

 ous-glandular, the uppermost usually exceeding the inflorescence; heads numerous, in 

 dense elongated racemes; involucre 9 to 12 mm. high; bracts 10 to 15, obscurely ranked, 



