Gray Green Thistle - Cirsium canovirens
Cirsium cymosum, Cirsium subniveum, Cirsium inamoenum
(see State Rank Reason below)
MNPS Threat Rank
State Rank Reason (see State Rank above)
Cirsium canovirens is treated as a variety (Cirsium cymosum variety canovirens) by the Flora of North America (FNA 2006). Whether treated at the species or variety level this plant occurs in southwest Montana where it is fairly common. In general thistles are under-collected, and more location data would be welcomed.
- Details on Status Ranking and Review
ScoreC - 250 - 1,000 individuals
ScoreD - 1,000-5,000 sq km (~400-2,000 sq mi)
Area of Occupancy
ScoreC - 3-5 4-km2 grid cells
Number of Populations
ScoreB - 6 - 20
Number of Occurrences or Percent Area with Good Viability / Ecological Integrity
ScoreC - Few (4-12) occurrences with excellent or good viability or ecological integrity
ScoreC - Moderate. Generalist or community with some key requirements scarce
ScoreD - Low
CommentNo known threats.
Taprooted biennial. Stems erect, branched above or not, 30–100 cm, sometimes with spiny wings from leaf bases. Herbage tomentose to arachnoid, upper leaf surfaces sometimes sparsely so. Leaves short-petiolate; blade linear-oblanceolate, 8–25 cm long, pinnately lobed, becoming clasping or decurrent upward. Inflorescence heads 1 to few at tips of peduncles forming corymbiform arrays; peduncles 1–8 cm long. Involucres broadly campanulate, 15–30 mm high, sparsely arachnoid-tomentose; phyllaries imbricate in 6 to 10 series, green, linear-lanceolate; sometimes with a darkened, often resinous midvein; spines 2–6 mm long, spreading. Disk corollas white to light purple, 15–26 mm long. Achenes 5–8 mm long (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
OR to MT to CA, NV and WY (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
- Literature Cited AboveLegend: View Online Publication
- Cronquist, A., A.H. Holmgren, N.H. Holmgren, J.L. Reveal, and P.K. Holmgren. 1994. Intermountain Flora: Vascular Plants of the Intermountain West. Asterales. U.S.A., Volume 5. Published for The New York Botanical Garden, Bronx, New York.
- Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.