Budsage is well adapted to xeric conditions. It has an extensive root system that 

 grows primarily in the top 15 to 55 cm of soil. Interxylary cork is formed annually 

 over the last year's wood in both the roots and the stem. This layer of cork restricts 

 the upward movement of water to the very narrow zone of wood formed by the current 

 year's growth. The corky tissue develops during early summer and thus helps to prevent 

 excessive water loss during the dormant season (Wood 1966]. Many other xerically adapt- 

 ed woody Artemisias also have interxylary cork (Moss 1940]. 



Budsage bears small flower heads (3 to 5 mm long] in glomerate racemes of 1 to 3 

 heads in leaf axils of the flower branches. Each head contains 2 to 6 fertile, pistil- 

 late ray flowers and 5 to 13 perfect but sterile disc flowers with abortive ovaries. 



The loose flower heads are held together by long, matted hairs that cover the co- 

 rolla and especially the achenes. The heads fall from the plant intact, without break- 

 ing apart to release the seed. Seeds germinate in some instances, while still in the 

 head (Wood 1966]. Good seed production occurs infrequently. The flowers bloom so early 

 in the spring that developing embryos frequently are frozen. Abundant reproduction 

 occurs in years of plentiful seed and favorable moisture. 



Terminal and lateral buds of budsage generally expand and begin to elongate in 

 late March and early April during the latter part of the "slipping" period. Blooming 

 normally occurs from the last week in April through the last week in May, although it 

 has been found in bloom as early as late March and as late as mid-June (Wood 1966]. 

 Cleaned seed averages 4,855 per gram (2,200,000 per pound]. 



Although budsage ordinarily begins growth early in the spring and then becomes 

 dormant by early or midsummer, it occasionally may break dormancy in response to late 

 summer storms. The plants then remain green all winter to provide succulent forage 

 throughout the winter and spring. 



As a species, budsage is distinguished by its spinescent habit and low variability 

 in involucre and floral characteristics. The harsh environment in which budsage grows 

 has perhaps helped to stabilize this species so that no variants have yet been recog- 

 nized and named. 



Hybridization. --Artemisia spinescens has chromosome numbers of 2n = 18 and 2n = 36 

 (Powell and others 1974; McArthur and Pope 1977]. It is not known to hybridize with 

 any other species. Its tetraploid form is thought to be autotetraploid (McArthur and 

 Pope, data on file at the Shrub Sciences Laboratory, Provo, Utah]. 



Distribution and habitat. — Budsage is a very drought-resistant shrub found on dry, 

 often saline plains and hills from southwestern Montana, central Idaho, and eastern 

 Oregon southward to southeast California, New Mexico, Arizona, and Colorado. Type 

 locality is "Rocky Mountain plains, in arid deserts, toward the north sources of the 

 Platte" (Abrams and Ferris I960]. It is often associated with shadscale, black grease- 

 wood (Sarcobatus vermiaulatus) , and other salt-tolerant shrubs. In some areas, it is 

 associated with black sagebrush and basin big sagebrush. 



i/se. --Budsage is a palatable, nutritious forage plant for upland birds, small game, 

 big game, and sheep in the winter. Generally, it is more palatable in the late winter 

 than during the early winter (Holmgren and Hutchings 1972] . During this time it is of 

 tremendous value to the welfare of grazing animals, especially where there is an 

 abundance of dry grass. 



Care must be taken in grazing budsage in late winter and early spring. Even light 

 grazing during this period is detrimental, and continual, heavy grazing may eliminate 

 budsage from the area (Holmgren and Hutchings 1972]. 



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