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Weber's Saw-wort - Saussurea weberi
State Rank Reason (see State Rank above)
DRAFT: Requesting feedback on the 2026 revised rank, factors, and State Rank Reason outlined below and in the Conservation Status Rank Report.
Saussurea weberi is extremely rare in the state with only two known occurrences. Only the one occurrence is apparently moderate to large in population size. Threats to the species appear to be limited as a result of its remote, alpine habitat and are limited to potential impacts related to changes in climate.
Current data are needed for both occurrences on population size and extent. Surveys in other areas of suitable habitat may find additional populations.
General Description
Weber's Saw-wort is a dwarf perennial herb that is 5-20 cm high and arising from a woody rootstock. The lance-shaped leaf blades are coarsely toothed, up to 8 cm long, and have a broad petiole. The alternate leaves are crowded on the stem, reduced, and lacking petioles towards the top. Herbage is covered with long, tangled hairs when young but becomes glabrous with age. The purple flowering heads are borne in a dense cluster subtended by leaves at the top of the stem. The broad involucral bracts of the heads have rounded tips and are 11-15 mm long. All of the flowers are tubular (disk flowers); ray flowers are absent. The achene has a pappus on top.
Phenology
Flowering in July-early August.
Diagnostic Characteristics
The clustered, purple, rayless flowering heads, together with the high elevation habitat, are distinctive. The similar S. densa, occurring in the northwest mountains, has narrow, pointed involucral bracts.
Species Range
Montana Range
Range Descriptions
Native
Range Comments
Regional endemic of southwest Montana, northwest Wyoming, and central Colorado.
Observations in Montana Natural Heritage Program Database
Number of Observations: 9
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
Relative Density
Recency
(Observations spanning multiple months or years are excluded from time charts)
Habitat
Moist meadows in the alpine zone.
National Vegetation Classification System Groups Associated with this Species
Alpine
Alpine - Vegetated
Wetland and Riparian
Alpine Riparian and Wetland
Stewardship Responsibility
Threats or Limiting Factors
STATE THREAT SCORE REASON
Threat impact not assigned because threats are not known (MTNHP Threat Assessment 2021).
References
- Literature Cited AboveLegend:
View Online Publication
MTNHP Threat Assessment. 2021. State Threat Score Assignment and Assessment of Reported Threats from 2006 to 2021 for State-listed Vascular Plants. Botany Program, Montana Natural Heritage Program, Helena, Montana.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?- Achuff, P. L. and L. S. Roe. 1992. Botanical survey of the Goat Flat proposed Research Natural Area, Deerlodge National Forest. Unpublished report to the Deerlodge National Forest. Montana Natural Heritage Program, Helena, MT. 31 pp.
- Lackschewitz, K. H. 1976. Montana mountain flora: new records. Madrono 23:360-362.
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.
- Marriott, H. 1991. Field survey for Androsace chamaejasme var. Carinata and Saussurea weberi, Northwest Wind River Range, Wyoming. Unpublished report to the Bridger-Teton National Forest. Wyoming Natural Diversity Database, The Nature Conservancy. 21 pp.
- Watson, T.J. and K.H. Lackschewitz. 1980. The genus Saussurea (Asteraceae-Cynareae) in Montana. Northwest Science 54(2):106-108.
- Web Search Engines for Articles on "Weber's Saw-wort"
