INTRODUCTION 



The sunflower family is the largest family of flowering plants. Its many species 

 occur around the world (Benson 1957; Cronquist 1968) . The family is well defined but 

 diverse. Wagentiz (1976) stated, "The range of variability" of the sunflower family 

 "in life form and other vegetative characters is . . . impressive if we remember the 

 (family's) numerous annual herbs, herbaceous perennials, shrubs, and trees." It con- 

 tains many beautiful, popular garden flowers, a large number of weeds, numerous useful 

 wildland forbs, and some woody genera, including important browse species. 



Four genera of this family, sagebrush (Artemisia), rabbitbrush {Chrysotharmus) , 

 horsebrush {Tetradymia) and matchweed [Xanthoaephalum) , are among the most common and 

 important shrubs on western ranges. Approximately 11 percent (2,514,000 hectares or 

 9,700 square miles) of Utah is dominated by various species of sagebrush. These species 

 produce the highest volume of forage of the various shrublands within the State (West 

 1974). Approximately 109,400,000 hectares (422,000 square miles) in the Western States 

 have sagebrush in varying amounts growing on them (Beetle 1960) . Horsebrush, matchweed, 

 and rabbitbrush, particularly rubber rabbitbrush (C. nauseosus) and low rabbitbrush 

 (C. viscidifloTus), are commonly associated with sagebrush throughout the western 

 United States. 



Shrubs of these genera provide critically needed ground cover on arid western 

 ranges, are important sources of browse for domestic livestock and big game, and serve 

 as cover and forage for wildlife. Various forms of sagebrush and rabbitbrush may also 

 be used for landscaping and for stabilizing and beautifying disturbed landscapes. 

 Young wildings of both sagebrush and rabbitbrush transplant easily. Usually within 

 3 to 7 years they are established sufficiently to reproduce naturally from seed. Both 

 establish well when aerially seeded (Plummer and others 1968; McArthur and others 1974; 

 Plummer 1977) . 



The purpose of this paper is to document what is known about shrubs of the sun- 

 flower family in the Intermountain area, particularly their vegetative and flowering 

 characteristics, hybridization, distribution, and use. flost of the observational in- 

 formation and experimental data were gathered from the Intermountain area, especially 

 from Utah. The Intermountain area includes all of Utah, that portion of Arizona north 

 of the Grand Canyon, most of Nevada, parts of California that lie within the Great 

 Basin, the sagebrush areas of southeastern Oregon, southern Idaho to the high mountain- 

 ous areas to the north, and the Red Desert area of southwestern Wyoming (Holmgren and 

 Reveal 1966) . However, reference to and comments on species distribution and character- 

 istics outside this area are made as appropriate. 



Each species, its hybridization, distribution and habitat, and use are described 

 in detail. Each genus and its species and subspecies included in this publication are 

 arranged in alphabetical order. A taxonomic key (appendix) is given for the included 

 genera, species, and subspecies. This paper is the third in a series on Intermountain 

 shrub species; the first was on the Rose family and the second was on the Chenopod 

 family (Blauer and others 1975, 1976). 



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