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Montana Field Guides

Slender-branched Popcorn-flower - Plagiobothrys leptocladus

Species of Concern
Native Species

Global Rank: G4
State Rank: S2S3
(see State Rank Reason below)
State Threat Score: No Known Threats
C-value: 6

Agency Status


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State Rank Reason (see State Rank above)
Rare in Montana, where it is known from a few widely scattered sites in the state. Additional data on population levels, trends and threats to the known ocuurences are needed to more precisely evaluate its status. As it occurs in drying mud of ponds, wetlands, stockponds, etc it is likely that additional populations exist in Montana.
  • Details on Status Ranking and Review
    Slender-branched Popcorn-flower (Plagiobothrys leptocladus) Conservation Status Review
    Review Date = 06/06/2012
    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 - 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).


    ScoreNA - Rank factor not assessed.


    ScoreNA - Rank factor not assessed.

    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 8 total points scored out of a possible 13 (Rarity factors only).

General Description
Slender-branched Popcorn-flower is an annual that branches at the base into several prostrate stems that are 5-15 cm long. The strap-shaped leaves are up to 5 cm long and are opposite at the base but alternate above. Foliage is glabrous to sparsely covered with stiff hairs. The sessile flowers are borne at the branch tips in crowded, narrow, 1-sided, curved spikes that unwind as they mature. The white flowers have 5 narrowly lance-shaped, densely hairy sepals that elongate and bend to the same side in fruit. The minute, tubular corolla is as long as the sepals and flares into 5 spreading lobes. There are 4 lance-shaped, bristly nutlets that are 1-3 mm long, each with a prominent ridge on the inner face.

Flowering and fruiting in July-August.

Diagnostic Characteristics
The enlarged sepals, all bent to one side in fruit separate this species from the more widespread P. scouleri. Species of Cryptantha are similar, but none of our species are prostrate or occur in wet habitats. A hand lens will be needed for positive identification.

Species Range
Montana Range Range Descriptions


Range Comments
OR to MT, south to UT and Baja, CA. Disjunct.

Observations in Montana Natural Heritage Program Database
Number of Observations: 19

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

Drying mud on the shores of ponds in the plains and foothill zone.
Predicted Suitable Habitat Model

This species has a Predicted Suitable Habitat Model available.

To learn how these Models were created see

Ecological Systems Associated with this Species

Threats or Limiting Factors
Threat impact not assigned because threats are not documented. (MTNHP Threat Assessment 2021).

  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.
    • Quire, R.L. 2013. The sagebrush steppe of Montana and southeastern Idaho shows evidence of high native plant diversity, stability, and resistance to the detrimental effects of nonnative plant species. M.Sc. Thesis. Bozeman, MT: Montana State University. 124 p.
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Citation for data on this website:
Slender-branched Popcorn-flower — Plagiobothrys leptocladus.  Montana Field Guide.  .  Retrieved on , from