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Montana Field Guide

Montana Field Guides

Macoun's Draba - Draba macounii

Species of Concern

Global Rank: G5?
State Rank: S2S3
* (see State Rank Reason below)

Agency Status
USFWS:
USFS:
BLM:
MNPS Threat Rank: 3
C-value:

External Links






State Rank Reason (see State Rank above)
Known in Montana from only a few occurrences in Glacier National Park. Current population levels and trends are unknown. However, its high-elevation habitat is relatively inaccessible, and there are no obvious threats. Additional sites are likely to be documented.
  • Details on Status Ranking and Review
    Macoun's Draba (Draba macounii) Conservation Status Review
    Review Date = 11/01/2012
    View State Conservation Rank Criteria
    Population Size

    Score2-3 - Very Small to Small: Population size is imprecisely known but is believed to be <10,000 individuals.

    Range Extent

    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.

    Area of Occupancy

    Score2 - Low: Generally occurring in 4-10 Subwatersheds (6th Code HUC’s).

    Environmental Specificity

    Score1-2 - Moderate to High.

    Trends

    Score0-1 - Stable to Minor Declines:

    CommentTrends unknown, though populations are likely stable or experiencing only minor declines.

    Threats

    Score0-1 - Low to Medium.

    Intrinsic Vulnerability

    Score1 - Moderate Vulnerability: Specific biological attributes, unusual life history characteristics or limited reproductive potential makes the species susceptible to extirpation from stochastic events or other adverse impacts to its habitat and slow to recover.

    Raw Conservation Status Score

    Score 7 to 11 total points scored out of a possible 19.

 
General Description
Macoun's Draba is a low perennial herb with few to many leafless stems that are 1-4 cm high and which arise from leaf rosettes that, in turn, arise from the ends of a simple or branched rootcrown. The broadly lance-shaped leaves are 6-10 mm long and are glabrous to sparsely covered with branched hairs; the leaves have long straight hairs on the entire margins. The stalked flowers are borne at the tops of the stems in a compact inflorescence. Each flower has 4 separate sepals, 4 separate, white petals, and 4 long and 2 short stamens. The style is ca. 0.5 mm long. The glabrous, flattened, broadly elliptic capsules are 4-8 mm long and are borne on ascending or spreading stalks.

Phenology
Flowering in July.

Diagnostic Characteristics
There are many similar-appearing species of Draba in our area. A technical manual and hand lens or microscope are required for positive identification. The relatively broad leaves, compact inflorescence, and wide capsules help separate this species from D. lonchocarpa, a more common white-flowered species.

Species Range
Present
 


Range Comments
AK to MT, and CO. Known from Flathead and Glacier counties (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Summary of Observations Submitted for Montana
Number of Observations: 5

(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
Wet rock ledges and moist tundra in the alpine zone.

Ecological Systems Associated with this Species

References
  • Additional ReferencesLegend:   View Online Publication
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    • Lesica, P. and B. McCune. 1992. Monitoring the effects of global warming using peripheral rare plants in wet alpine tundra in Glacier National Park, Montana. Unpublished report to Glacier National Park, Research Division, West Glacier, Montana 59936. 55pp.
    • Lesica, P., K. Lackschewitz, J. Pierce, S. Gregory and M. O'Brien. 1986. Noteworthy collections: Montana. Madrono 33:310-312.
    • Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
    • Mulligan, G.A. 1976. The genus Draba in Canada and Alaska: key and summary. Canadian Journal of Botany 54:1386-1393.
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Citation for data on this website:
Macoun's Draba — Draba macounii.  Montana Field Guide.  .  Retrieved on , from