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Montana Field Guide

Montana Field Guides

Latah Tule Pea - Lathyrus bijugatus

Species of Concern

Global Rank: G4
State Rank: S2S3
* (see State Rank Reason below)

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

External Links






State Rank Reason (see State Rank above)
Rare and peripheral in Montana. Currently documented from three, widely scattered sites in the valleys-lower mountains of northwest Montana.
  • Details on Status Ranking and Review
    Latah Tule Pea (Lathyrus bijugatus) Conservation Status Review
    Review Date = 06/07/2012
    View State Conservation Rank Criteria
    Population Size

    Score1 - Moderate: Generally 10,000-100,000 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

    Score3 - Very Low: Generally occurring in 3 or fewer Subwatersheds (6th Code HUC’s).

    CommentAdditional surveys would likey find other locations. 1 occurrence is only known from an historical collection with imprecise locality data.

    Environmental Specificity

    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).

    Trends

    Score0-2 - Stable to Moderate Declines:

    Threats

    Score0-2 - Low to High Threat Levels.

    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
Latah Tule Pea is an herbaceous perennial with erect stems that stand 1-3 dm tall and arise from slender rhizomes. The alternate leaves have 2-4 paired, strap-shaped to oblong leaflets that are 2-15 cm long and a bristle instead of a tendril on the tip. Each leaf has a pair of narrow, leaf-like wings, or stipules at the point of stem attachment. Foliage is glabrous to sparsely short-hairy. 2-3 pink to light blue, pea-like flowers, 10-13 mm long, are borne on ascending stalks in the axils of the upper leaves. The upper petal is reflexed upward and equal in length to the wing petals but longer than the keel petals. The calyx is 6-8 mm long and has 5 pointed lobes. The fruit is a flattened, elongate-elliptic pod that is 3-4 cm long with 7-12 seeds.

Phenology
Flowering in June.

Diagnostic Characteristics
Vicia americana and Lathyrus ochroleucus have a tendril instead of a bristle on the leaf tip.

Species Range
Present
 


Range Comments
Known from Flathead and Lincoln counties. Endemic to ID, adjacent WA and MT (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Summary of Observations Submitted for Montana
Number of Observations: 8

(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
Open ponderosa pine and western larch forests in the valley and lower montane zones.

Ecological Systems Associated with this Species

References
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Citation for data on this website:
Latah Tule Pea — Lathyrus bijugatus.  Montana Field Guide.  .  Retrieved on , from