Lackschewitz' Milkvetch - Astragalus lackschewitzii
State Rank Reason (see State Rank above)
Montana endemic restricted to high elevation, gravelly and rocky slopes and ridges. Several of the known occurrences are in designated wilderness and the habitats occupied by the species are not generally subject to human disturbance.
- Details on Status Ranking and Review
Score1 - Moderate: Generally 10,000-100,000 individuals.
Score3 - Local Endemic or Very Small Montana Range: Generally restricted to an area <10,000 sq. miles (equivalent to the combined area of Phillips and Valley Counties) or <6 Sub-basins (4th code watersheds) Range-wide OR limited to one Sub-basin in Montana
Area of Occupancy
Score2-3 - Very Low to Low. Occurs in 10 or fewer Subwatersheds (6th Code HUC’s), though the species' distribution is not sufficiently documented to place it within one class.
CommentSpecies often occurs near or along the upper boundaries the watersheds.
Score1-2 - Moderate to High.
Score0-1 - Stable to Minor Declines:
CommentTrends unknown, though populations are likely stable or experiencing only minor declines.
Score0-1 - Low to Medium.
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
8 to 12 total points scored out of a possible 19.
Lackschewitz' Milkvetch is a low and loosely tufted or matted perennial, with prostrate or ascending stems less than 10 cm long, arising from a branched rootcrown. Leaves are alternate on the stem, 2.2-5.8 cm long, with 15-23 ovate or elliptic leaflets; the upper leaflet surface is glabrous and the lower surface and outer margins have short hairs. The 3-5 pea-like flowers are borne in an open, upright inflorescence that often becomes prostrate as fruits mature. Petals are 8.5-11.2 mm long and purplish-blue. The calyx is 2.5-3.8 mm long and covered with uniformly short, straight black hairs sometimes intermixed with white. The oval or elliptic pod is 9-11.2 mm long, curved upward, and triangular in cross section, with a groove at the bottom, and covered with short hairs.
Flowering and fruiting in July-August.
The other two Astraglus species that are small, low-growing species on limestone at high elevations in nothwest Montana are A. alpinus and A. bourgovii. The former differs from A. lackschewitzii in having leaflets that are blunt at the tip and pods that are almost completely divided into two chambers. The latter differs in that it has pods which are oval in cross-section.
Endemic to the Rocky Mountain front range in west-central Montana, Teton County (Lavin and Marriott 1997).
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, gravelly, calcareous soil and talus on ridge tops and slopes in alpine or subalpine zones.
Ecological Systems Associated with this Species
- Commonly Associated with these Ecological Systems
- Occasionally Associated with these Ecological Systems
- Additional ReferencesLegend: View Online Publication
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- Lavin, M. and H. Marriott. 1997. Astragalus molybdenus s.l. (Leguminosae): Higher taxonomic relationships and identity of constituent species. Systematic Botany 22(2):199-217.
- Lavin, M., S. Mathews, C. Hughes, H. Marriott and S. Shelly. 1990. Intraspecific chloroplast DNA diversity is high in some wild species of Leguminosae. Amer. J. Bot. 77 (supplement):144 (abstract).
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Phillips, H. Wayne. Lewis and Clark National Forest, 1101 15th Street North, P.O. Box 869, Great Falls, MT 59403. 406/791-7743. Personal Communication to the Montana Natural Heritage Program.
- Schassberger, L.A. 1989. Field surveys of the Front Range Mountains, 7-10 and 21-23 August (Astragalus lackschewitzii).
- Schassberger, L.A. And J.S. Shelly. 1990. Status Review and Taxonomic Studies of Astragalus molybdenus, Lewis and Clark National Forest. Unpublished Report. Montana Natural Heritage Program, Helena, MT 45 pp.
- Shelly, J. S. 1989. Field Survey in Teton County of 7-10, 21-23, and 28-30 August.