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Macoun's Cinquefoil - Potentilla macounii
Other Names:  Potentilla concinna var. macounii

Native Species

Global Rank: G3?
State Rank: S3S4
* (see State Rank Reason below)

Agency Status
USFWS:
USFS:
BLM:
MNPS Threat Rank:
C-value:

External Links






State Rank Reason (see State Rank above)
Potentilla macounii is a regional endemic occurring in Montana and Alberta (FNA 2014). It is a Species of Concern in Alberta (FNA 2014), but appears common in central Montana. However, it can easily be misidentified and several specimens in the herbaria need to be re-evaluated. Current information on locations, population sizes, and threats is needed.
  • Details on Status Ranking and Review
    Macoun's Cinquefoil (Potentilla macounii) Conservation Status Review
    Review Date = 11/05/2012
    View State Conservation Rank Criteria
    Population Size

    Score1-2 - Small to Moderate. Population size is imprecisely known but is believed to be >2,000 individuals and <100,000 individuals.

    CommentEstimated. Population levels are undocumented.

    Range Extent

    Score2 - Regional or State Endemic or Small Montana Range: Generally restricted to an area <100,000 sq. miles (equivalent to 2/3 the size of Montana or less) or Montana contributes 50% or more of the species’ range or populations OR limited to 2-3 Sub-basins in Montana.

    Area of Occupancy

    Score0-1 - Moderate to High. Occurs in >10 Subwatersheds (6th Code HUC’s), though the species' distribution is not sufficiently documented to place it within one class.

    Environmental Specificity

    Score0-1 - Low to Moderate.

    Trends

    ScoreNA - Rank factor not assessed.

    Threats

    ScoreNA - Rank factor not assessed.

    Intrinsic Vulnerability

    Score0-1 - Low to Moderate Vulnerability.

    Raw Conservation Status Score

    Score 5 to 11 total points scored out of a possible 19.

 
General Description
Perennial with a branched caudex clothed in old leaf bases. Stems prostrate to ascending, sericeous, 3–10 cm. Leaf blades cordate-ovate, pinnately divided into 5 to 7 pinnately toothed leaflets, 5–15 mm long, sparsely to densely sericeous above, white-tomentose beneath. Inflorescence a few-flowered, sericeous cyme with spreading branches. Flowers: sepals broadly lanceolate, 4–7 mm long with narrower bracteoles 3–5 mm long; petals yellow, 5–8 mm long, truncate. Achenes smooth, about 2 mm long (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Phenology
Flowering in early summer (FNA 2014).

Diagnostic Characteristics
Barry Johnston in his 1980 monograph of Potentilla section Multijugae supports recognition of this taxon at the specific level, in a section different from that of P. concinna. This he based on characters of style shape and texture and leaf lobing pattern. However, this monograph is a Doctoral thesis so did not undergo the same peer-review process that a published article would.

The Potentilla treatment by authors Ertter, Elven, Reveal, and Murray in Flora of North America, Volume 9 (2014) accepted Potentilla macounii as a distinct species in Section Concinnae based on a combination of characteristics: subpinnate leaves where at least two proximal pairs of leaflets well separated from the terminal leaflets and plants having somewhat softer hairs.

Potentilla macounii has at least 2 leaflets on the petiole that are well separated from the terminal leaflets plus the inflorescence has 1-5 flowers, stipules are entire or shallowly lobed, bracteoles are shorter than sepals, petals are longer than sepals, and style is at least 2 mm long. In Potentilla concinna leaflets are attached at the tip of the petiole (Lesica et al. 2012). In Potentilla pensylvanica the stipules are deeply lobed, bracteoles are equal or longer than the sepals, and the styles are 1.2 mm or less. In Potentilla hippiana the inflorescence usually has more than 5 flowers and the petals and sepals are similar in length. In Potentilla rubicaulis the inflorescence usually has 1-5 flowers, but the styles are about 1 mm long.

Range Comments
Endemic to Alberta and Montana (FNA 2014). Specimens collected from the Absaroka Range in western Wyoming are similar to Potentilla macounii, but have a softer vestiture and somewhat larger, less divided and more subpalmate leaves, and occur up to 3,300 meters (FNA 2014).

Observations in Montana Natural Heritage Program Database
Number of Observations: 37

(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
Sandy to gravelly, shallow, often calcareous soil of grasslands, woodlands, outcrops; valleys, montane (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Ecological Systems Associated with this Species

References
  • Literature Cited AboveLegend:   View Online Publication
    • Flora of North America Editorial Committee, eds. 2014. Flora of North America north of Mexico, Volume 9. Magnoliophyta: Picramniaceae to Rosaceae. Oxford University Press, Inc. New York.
    • Johnston, B. C. 1980. Studies of population variability leading to a new classification of Potentilla sect. Multijugae (Rosaceae). Ph.D. dissertation. Boulder, CO: University of Colorado.
    • Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
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Citation for data on this website:
Macoun's Cinquefoil — Potentilla macounii.  Montana Field Guide.  .  Retrieved on , from