2. State. 



a. Montana. 



i 



i. Present designated or proposed 

 legal protection or regulation: 



None. 



ii. Other current formal status 

 recommendations: Cirsium 

 lonqistylum has most recently 

 been ranked by the Montana 

 Natural Heritage Program as an 

 S2 species ("imperiled in 

 Montana because of rarity (6-20 

 occurrences") (Shelly 1990) . 

 Although only 20 populations of 

 C. lonqistylum are currently 

 recorded, several contain tens 

 of thousands of individuals and 

 numerous other populations were 

 observed that were not recorded. 

 Thus, the rank will be changed 

 to S3 on the 1991 list of Plant 

 Species of Special Concern. 



iii. Review of past status: 



Previously listed as "rare in 

 Montana" by the Montana Rare 

 Plant Project (Lesica et al. 

 1984) . 



3. Description. 



I 



A. General nontechnical description: Cirsium 



lonqistylum is a perennial thistle from thick, woody 

 underground stems. The stems are 20-24 inches tall, 

 ribbed, and are lightly hairy with long, cobwebby 

 hairs. The basal rosette leaves are somewhat spiny, 

 shallowly lobed, and are green, hairless above and 

 densely white hairy below. The stem leaves are 

 gray-green with long white cobwebby hairs, narrowly 

 spear-shaped, about 10 times as long as wide (up to 

 6 inches long and 0.5 inch wide), with lobes about 

 1/3 the width. Smaller leaves are only shallowly 

 lobed with numerous fine marginal spines to 0.2 inch 

 long. The flower heads are about 1.2 inches high 

 and 1 inch wide, usually in a tight cluster in the 

 top 2/3 of the plant. In young plants, the upper 

 part of the stem may be unexpanded and the flowers 

 clustered at the top of the stem. The flower heads 

 have a few small leaves beneath, the uppermost 



