}0() MISC. PUBLICATION 303, U. S. DEPT. OF AGRICULTURE 



A small shrub ; occurs on sandy, alkaline plains ; flowers August-September ; 

 greatly increased by overgrazing. Of some slight value as browse for livestock 

 where other feed is not available. 



Chrysothamnus hu'milis, see Chrysothamnus visoidiflorus. 

 Chrysothamnus latifolius, see Chrysothamnus viscidiflorus. 

 Chrysothamnus leiospermus, see Chrysothamnus nauseosus. 

 Chrysothamnus linifolius, see Chrysothamnus visoidiflorus. 

 Chrysothamnus marianus, see Chrysothamnus viscidiflorus. 

 Chrysothamnus monocephalus, see Chrysothamnus parryi. 



Chrysothamnus nauseosus (Pallas) Britt. Eubber rabhitbrush. 



Chrysocoma nauseosa Pallas. 



Range : 4, 6, 7, 8, 9, 11, 12, 13, 14, 15. 

 Site: Dry, sun. 

 Fruit: Achene. 



A small to large shrub ; flowers September-December ; root system deep ; re- 

 produces readily from seed and grows vigorously when transplanted, even when 

 crowns are divided ; forms basal sprouts after cutting ; contains on the average 

 2.8 percent of rubber, although this may increase to 6.5 percent in individual 

 plants ; the most constant producers are those forms inhabiting alkali soils ; it 

 has been estimated that 300 million pounds of good-grade rubber are represented 

 in this country by this species, but extraction is not yet commercially profitable. 



Twenty subspecies or varieties are included within this species ; they rep- 

 resent the species in various sections of the Great Basin and adjacent areas. 

 C. nauseous includes the following forms : 



C. bigelovii (Gray) Greene, C. collinus Greene, C. concolor Rydb., C. consimilis 

 Greene, C. glareosus Rydb., C. graveolens (Nutt.) Greene, C. leiospermus (Gray) 

 Greene, C. occidentalis Greene, C. oreophilus Nels., C. pinifolius Greene, 

 C. pulcherrimus Nels. (more robust), C. salicifolius Rydb., C. speciosus Nutt., 

 C. turbinatus Rydb. 



Certain forms, as consimilis and viridulus, form pure stands on alkali flats ; 

 in general the important varieties are subclimax dominants of the sagebrush 

 association. 



Observations: Northward it furnishes an important winter browse for elk and 

 perhaps moose; California mule deer. Value as browse for livestock depends 

 on local conditions ; palatability ordinarily very low ; probably poisonous when 

 eaten exclusively ; a not infrequent indicator of overgrazing. 



Chrysothamnus newberryi, see Chrygothamnus parryi. 

 Chrysothamnus occidentalis, see Chrysothamnus nauseosus. 

 Chrysothamnus oreophilus, see Chrysothamnus nauseosus. 



Chrysothamnus paniculatus (Gray) Hall. Sticky rabbitbrush. 



Bigelovia paniculata Gray, Ericameria paniculata (Gray) Rydb. 

 Range: 10. 

 Site: Dry, sun. 

 Fruit : Achene. 



A small to large, brittle-twigged shrub ; flowers May-October ; resistant to 

 low temperatures ; grows in extremely poor soils ; rubber content about 2.5 per- 

 cent, but strains may be found containing a higher percentage. 



Chrysothamnus parryi (Gray) Greene. 



Linosyris parryi Gray, Bigelovia parryi Gray. 



Range : 4, 8, 9, 10, 11, 12, 13, 15. 



Site : Dry, well-drained, sun. 



Fruit: Achene. 



A small shrub occurring on sandy or gravelly soils; an indicator of over- 

 grazing. Ten subspecies or varieties are recognized which do not separate on 

 stable characters but which are more or less separated geographically; the 

 whole complex is here considered a single major species. It includes among 

 others : C. asper Greene, C. newberryi Rydb. C. vulcanicus Greene, C. mono- 

 cephalus Nels. and Ken., and C. wyomingensis Nels. 



Chrysothamnus pinifolius, see Chrysothamnus nauxeosus. 



