40 



the 1984 Forest Service Manual. Under these 

 guidelines, the Forest Service is to (a) 

 "maintain viable populations of all native 

 species of plants" (2670.22), and (b) "avoid 

 or minimize impacts to species whose 

 viability has been identified as a concern" 

 (2670.32.3) . 



STATE: Cirsium subniveum is listed by the Montana 

 Natural Heritage Program as "very rare and local 

 within its range" (global rank G3G4) by the 

 Montana Natural Heritage Program (Shelly 1990) . 

 This species is also listed for the state as 

 "imperiled in Montana because of rarity" (SI = 1-5 

 occurrences) . 



DESCRIPTION 



GENERAL NONTECHNICAL DESCRIPTION: This taprooted 

 perennial member of the thistle genus (Sunflower 

 Family) may grow to a height of 28 inches. The 

 freely branching stems are covered with long white 

 hairs, while the leaves are sparse woolly-hairy. 

 Leaf margins are coarsely lobed and like most 

 thistles, spine tipped. Solitary flowering heads 

 occur at the tips of branches; each head contains 

 25-50 tubular flowers. The flowers are white to 

 light pink, and each head is surrounded by a ring 

 of green bracts tipped by yellow spines. The 

 outer bracts are sharply spine tipped, while the 

 inner bracts are more lax. 



TECHNICAL DESCRIPTION: Perennial from a taproot, 

 3-7 dm tall, freely branching, the stem crisp- 

 villous to arachnoid-f loccose or rather thinly 

 tomentose, often eventually glabrate; leaves 

 rather thinly f loccose-tomentose beneath, greener 

 and more glabrate above; heads terminating the 

 branches; involucre mostly 17-25 mm high, more or 

 less arachnoid-tomentose, its rather broad bracts 

 contracted into erect or more spreading yellow 

 spines 3-8 mm long, the innermost slender, but 

 innocuous and somewhat twisted; flowers rather 

 pale pink or purplish (adapted from Hitchcock et 

 al. 1955-1969) . 



LOCAL FIELD CHARACTERS: Cirsium subniveum differs 

 from C. neomexicanum var. utahense in its smaller 

 and apparently less numerous-flowered heads. 

 Also, the bases of the leaves are decurrent in 

 this species, and it has a more northern and 

 montane distribution (Hitchcock et ai. 1955-1969, 



