Prairie Goldenrod - Solidago ptarmicoides
Oligoneuron album, Aster ptarmicoides
State Rank Reason (see State Rank above)
Rare in Montana, where it has been documented from only a few locations on the eastern plains.
- Details on Status Ranking and Review
Score3 - Vey Small: Generally <2,000 individuals.
CommentPopulation size unknown, but likely to be <2,000 plants based upon available data.
Score1 - Peripheral, Disjunct or Sporadic Distribution in MT: Widespread species that is peripheral, disjunct or sporadically distributed within MT such that it occurs in <5% of the state (<7,500 sq. miles or the combined area of Beaverhead and Ravalli Counties) or is restricted to 4-5 sub-basins.
CommentPeripheral in eastern Montana.
Area of Occupancy
Score2 - Low: Generally occurring in 4-10 Subwatersheds (6th Code HUC’s).
Score1 - Moderate: Species is restricted to a specific habitat that is more widely distributed or to several restricted habitats and is typically dependent upon relatively unaltered, good-quality habitat (C Values of 5-7).
Score0-2 - Stable to Moderate Declines:
CommentTrends are unknown, though there is no indication that the species' has experienced significant declines in Montana.
Score0-2 - Low to High Threat Levels.
CommentPotential threats to the species' viability are unknown.
Score0-1 - Low to Moderate Vulnerability.
Raw Conservation Status Score
7 to 12 total points scored out of a possible 19.
Prairie Aster has stems that are 1-7 dm high and clustered on a woody-thickened, branched rootcrown. The narrowly lance-shaped leaves near the base of the plant have entire margins and are petiolate and up to 20 cm long, while those on the upper stem are shorter, strap-shaped, and lacking petioles. Foliage is glabrous to slightly roughened. The 3-60 flower heads are borne in an open, flat-topped inflorescence. The glabrous, overlapping involucral bracts of each head are 5-7 mm long, each with a greenish apex and a prominent, thickened midrib. The 10-25 rayflowers are white and 5-9 mm long, and the numerous disk flowers are white. The achene is glabrous and has a pappus of bristles that are thickened toward the top.
This species differs from other Solidago in having white flowers, resembling species formerly placed in Aster (in its broader taxonomic sense). It can be distinguished from the latter by its flat-topped inflorescence, its thickened, involucral bracts that are often blunt at the tips, and the thickened pappus bristles.
SK to QC south to OK, OH and SC. Known from Richland and Wibaux counties (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
Open, dry grasslands, often on sandy soil or limestone on the plains.
Ecological Systems Associated with this Species
- Additional ReferencesLegend: View Online Publication
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- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Vanderhorst, J.P., S.V. Cooper, and B.L. Heidel. 1998. Botanical and vegetation survey of Carter County, Montana. Unpublished report prepared for the Bureau of Land Management. Montana Natural Heritage Program, Helena. 116 pp. + app.