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pedicels in loose terminal clusters. A photographic slide 

 of the plant is attached at the end of this report. 



2. Technical species description (for Tanacetum nuttallii , a 

 synonym, quoted from Cronquist 1955): 



Aromatic perennial with many slender stems 0.5-2 dm. tall, 

 often slightly woody at base, fibrous-rooted, or with a 

 short, deliquescently branched taproot; herbage closely 

 gray-tomentose; leaves appearing clustered at the base 

 because of the numerous short sterile shoots, mostly cuneate 

 and 3-toothed or -lobed at the apex, sometimes 4- to 5-lobed 

 or entire, up to about 1.5 cm long including the slender 

 base; heads several, mostly short-pedunculate in a 

 subcapitate cluster, small, the involucre only 3-4 mm high, 

 the disk 4-7 mm wide; receptacle glabrous, strongly convex; 

 pappus essentially wanting. 



3. Diagnostic characters: The genus Sphaeromeria is 

 distinguished from lowland species of Artemisia by the 

 arrangement of its flower heads in capitate clusters vs. 

 racemes or panicles. S. argentea differs from S. capitata 

 by having leaves which are merely toothed or shallowly lobed 

 rather than deeply lobed and flower heads borne on pedicels 

 in loose clusters rather than sessile in dense clusters. 



B. Current legal or other formal status 



1. Federal 



a. Bureau of Land Management: none 



b. U. S. Fish and Wildlife Service: none 



c. U. S. Forest Service: none 



2. State: The Montana Natural Heritage Program ranks 

 Sphaeromeria argentea G? and SI (Heidel 1994). The 

 undetermined global rank reflects a lack of knowledge on the 

 species distribution and abundance in other states. In 

 Montana, it is considered critically imperiled due to 

 rarity. 



C. Geographic distribution 



1. Species range: "central Idaho and adjacent Montana to 

 Wyoming; Nevada (Hitchcock and Cronquist 1973)," also in 

 northwestern Colorado (Weber 1987). 



2. Montana distribution: southern Beaverhead County; 

 Sphaeromeria argentea is now known from 5 sites in Montana, 

 in the drainages of Red Rock Creek (near Dell and Matador 



