126 HANDBOOK 14 8, U.S. DEPARTMENT OF AGRICULTURE 



1 . Plants without sagebrush odor or taste. 

 2. Seed-head or fruit clusters persistent, distinctive (even after 

 seeds have fallen), often conspicuous at a distance. 



[Alternate 2, p. 136.] 



3. Shrubs fall-blooming; flower heads braeted, with tiny, }'ellovv 

 disk flowers, ray flowers lacking; seed heads stalked, narrowly 

 cylindrical or bell-shaped, in usually broad (elongate in fetid 

 rubber rabbitbrush), roundish-topped end clusters; seed-head 

 bracts firm-papery, often keeled, overlapping, in 4 or 5 more 

 or less vertically ranked rows; "seeds" (achenes) hairy, 

 crowned by ring of whitish or tawny, hairlike bristles (pappus) ; 

 leaves often drying-persistent, threadlike to (mostly) linear, 

 1- and/or 3- to 5-nerved, plane or spirally twisted; leaf buds 

 not developing until spring or, when moisture and tempera- 

 ture favorable, clusters of tiny leaves remain in leaf-scar or 

 leaf-base axils; usually round-bushy shrubs 1-6 (or 8) feet- 

 high; common, often with sagebrush, in dry (sometimes in 

 alkaline) sites, e. Oreg., e. Wash. 



rabbitbrushes (Chrysothamnus spp.). 

 4. Twigs flexible, whitish or greenish, hairy (loosely white- 

 woolly-hairy, or grayish- to greenish-feltlike and so resin- 

 matted that scraping twig is necessary to detect hairiness), 

 not or indistinctly striate; seed heads to }{ inch long; seed- 

 head bracts to 25, in distinctly vertical ranks; leaves usually 

 1-nerved, plane; stems often with appreciable rubber con- 

 tent; shrubs with deep taproots, sprouting from base after 

 cutting but rarely after burning; reportedly somewhat 

 poisonous to livestock under certain conditions; varieties 

 (or subspecies) with various intergrading characters, often 

 hard to tell apart. 



rubber rabbitbrushes {Chrysothamnus nauseosus). 



4. Twigs brittle, white to pale green, hairless or minutely 

 stiff-hairy (finely sand-papery to the touch), sometimes 

 shiny, often sticky-resinous near seed heads or with resin 

 drops in leaf or leaf-scar axils, striate; seed heads to % inch 

 long; seed-head bracts to 15, often in indistinctly vertical 

 ranks, sometimes broadest near their bent-inward tips; 

 leaves 1- and/or 3- to 5-nerved, often spirally twisted, 

 usually linear (sometimes to nearly ){ inch wide); stems 

 usually much-branched from near base; varieties (or sub- 

 species) with various intergrading characters, often hard to 

 tell apart. 



Douglas rabbitbrushes (Chrysothamnus viscidiflorus) . 



3. Shrubs not fall-blooming (mallow ninebark, shinyleaf spires, 



creambush rockspirea, deerbrush ceanothus, redstem ceano- 



thus, smooth sumac, mountain-ashes, Pacific poison-oak, 



west ern poison-ivy) . 



5. Bark peeling in many layers; seed pods (follicles) usually 

 2 for each flower, in drooping, somewhat umbrella-shaped 

 clusters (corymbs) at tips of short side twigs; sucker shoots 

 common, usually stouter, taller than other branches, and 

 with smooth, deep reddish or purplish bark; buds with sev- 

 eral overlapping bud scales; leaf sears with 3 (rarely 5) 

 bundle traces and with a stipule scar on either side at top 



