THISTLE FAMILY 853 



27. C. oregana Nutt. Stem 3-6 dm. high, branched, sparingly hirsute; 

 leaves lanceolate, 2-4 cm. long, sessile; heads corymbose, discoid, peduncled, 

 10-12 mm. high, 12-18 mm. wide; bracts lance-linear, scarious-margined, resin- 

 ous-granuliferous and sparingly hirsute. Sandy banks: Wash. w Ida. n Calif. 

 Son. Jl-Au. 



13. ERICAMERIA Nutt. 



Very leafy shrubs or undershrubs, with resinous-dotted heath-like foliage. 

 Heads small, paniculate or corymbose; involucres oblong or campanulate; bracts 

 well imbricate, chartaceous or thinner, appressed, wholly destitute of herbaceous 

 tips or some of the outer looser, slightly foliaceous. Ligules yellow, few, some- 

 times solitary or wanting. Disk-corollas somewhat widening upwards, deeply 

 5-toothed, yellow. Appendages of the style-branches filiform or slender-subulate. 

 Achenes slender, usually pubescent. Pappus of fine and soft bristles. 



Heads radiate; bracts not in distinct ranks. 

 Leaves linear-filiform or linear-oblanceolate. 



Leaves linear-oblanceolate, rarely 15 mm. long, curved; flowers yellow. 



1. E. nana. 

 Leaves linear-filiform, mostly 15-20 mm. long, divaricate; flowers ochroleucous. 



2. E. resinosa. 

 Leaves oblong-oblanceolate, short-cuspidate. 3. E. cervina. 



Heads discoid; bracts distinctly 5-ranked. 4. E. paniculata. 



1. E. nana Nutt. Low shrub, 1-3 dm. high, densely branched, somewhat 

 glutinous, glabrous; leaves pointed, channelled; heads solitary or 1 or 2 together; 

 involucres about 6 mm. long; bracts linear-lanceolate, in 4 or 5 series; ray-flowers 

 about 4 ; disk-flowers 8 ; achenes hirsute. Aplopappus nanus D. C. Eat. Chrysoma 

 nana Greene. Rocky hills: Wash. Utah Ore. Submont. Au-S. 



2. E. resinosa Nutt. Shrub about 3 dm. high, branched, very glutinous; 

 heads solitary at the ends of the short branches; involucres 6-7 mm. high, sub- 

 tended by numerous small leaves; bracts linear-lanceolate, in 4 or 5 series; ray- 

 flowers about 6 and disk-flowers about 12; achenes hirsute. Aplopappus resin- 

 osus A. Gray. Rocky hills: Wash. Ida. Ore. Son. Jl-S. 



3. E. cervina (S. Wats.) Rydb. Low shrub about 1.5 dm. high; leaves 8-12 

 mm. long, entire, 3-nerved; heads in corymbs of 3-5, 6-8 mm. high; outer bracts 

 linear, acuminate, the inner chartaceous, acutish, with scarious margins; rays 

 few. Aplopappus cervinus S. Wats. Canons: Utah. 



4. E. paniculata (A. Gray) Rydb. Shrub 3-6 dm. high; branches densely 

 punctate; leaves numerous, involute-filiform, resinous-punctate and glabrous, 

 1-5 cm. long; heads paniculate: involucres about 6 mm. high, turbinate; bracts 

 linear. Chrysoma paniculata Greene. A. paniculatus A. Gray. Desert regions: 

 s Calif. s Utah. Son. 



14. CHRYSOTHAMNUS Nutt. RABBIT BRUSH. 



Shrubs or undershrubs, with narrow leaves. Inflorescence mostly paniculate- 

 cymose. Heads discoid; flowers all alike, 5-15; corollas yellow or in one species 

 nearly white. Bract coriaceous or chartaceous, in distinct (usually 5) vertical 

 rows, without herbaceous tips. Corollas 5-toothed, slender. Style-branches with 

 exserted, subulate or setaceous-filiform appendages. Achenes slender, terete or 

 slightly angled. Pappus of numerous slender bristles, white. 



Bracts of the involucre acuminate. 

 Achenes glabrous. 



Leaves oblanceolate or spatulate, scabrous-puberulent ; plant less than 2 dm . 



high. 1. C. dcpressus. 



Leaves narrowly linear, slighfclj tomentulose or glabrous. 



Bracts thick, strongly carinate, glabrous. 3. C. pulchellus. 



Bracts thin, not strongly carinate. arachnoid-ciliate. 2. C. Bigelovii. 

 Achenes pubescent, usually strigose. 



Bracts 4-6 in each vertical row. 3. C. pulchellus. 



Bracts 2-3 in each vertical row. 



Outer bracts long-acuminate, produced and more or less foliaceous. 

 Leaves linear, more or less distinctly 3-nerved. 4. C. Parryi. 



Leaves very narrowly linear, 1-nerved. 



Leaves and branches green, or the latter slightly tomentulose. 



5. C. attenuatus. 



