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Montana Field Guides

Long-leaf Evening-primrose - Camissonia subacaulis
Other Names:  Oenothera subacaulis

Native Species

Global Rank: G5
State Rank: S3S4
(see State Rank Reason below)
C-value: 5

Agency Status


External Links

State Rank Reason (see State Rank above)
Camissonia subacaulis is found in several counties and the most recent of observations indicate that where the plant is found it can be common.
  • Details on Status Ranking and Review
    Long-leaf Evening-primrose (Camissonia subacaulis) Conservation Status Review
    Review Date = 11/14/2016
    View State Conservation Rank Criteria
    Range Extent

    ScoreF - 20,000-200,000 sq km (~8,000-80,000 sq mi)

    Area of Occupancy

    ScoreE - 26-125 4-km2 grid cells

    Number of Populations

    ScoreC - 21 - 80

    Number of Occurrences or Percent Area with Good Viability / Ecological Integrity

    ScoreC - Few (4-12) occurrences with excellent or good viability or ecological integrity

    Environmental Specificity

    ScoreC - Moderate. Generalist or community with some key requirements scarce

    Long-term Trend

    ScoreU - Unknown


    ScoreU - Unknown


    ScoreU - Unknown

    CommentThreats: Unknown/undetermined.

General Description
Plants: Taprooted, short-lived, acaulescent perennial. Herbage glabrous (Lesica 2012), seldom with a few straight, stiff hairs (Hickman 1993).

Leaves: Petiolate, all basal; the blade lanceolate to oblanceolate, sometimes pinnately lobed below, 4–15 cm long (Lesica 2012).

Inflorescence: Flowers sessile in leaf axils (Lesica 2012).

(Lesica's contribution adapted from Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)

Flowers May-August (Niehaus & Ripper, 1976).

Diagnostic Characteristics
Similar to Oenothera flava, which has long stigma lobes, and to Camissonia breviflora, which has deeply incised leaves.

Species Range

Range Comments
WA to MT south to CA, NV, UT and CO (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Observations in Montana Natural Heritage Program Database
Number of Observations: 30

(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)

Substrate: Generally in clay soils (Hickman 1993).

Habitat: Grows in meadows that are moist in spring. In Montana, these meadows are found around persistent snow at moderate elevations.

Reproductive Characteristics
Flowers: 4-merous; hypanthium 2–5 cm long, the upper expanded portion 1–3 mm long; sepals 6–15 mm long, reflexed; petals 7–15 mm long, yellow (Lesica 2012); anthers joined at the base to the filament (Hickman 1993); stigma globose, slightly lobed (Lesica 2012).

Fruit: Capsule sessile, ovoid, 13–25 mm long, 4-sided (Lesica 2012); seeds in 2 lines per locule, light brown, 1.3-1.9 mm (Hickman 1993).

Usually cross-pollinated (Hickman 1993).

(Lesica's contribution adapted from Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)

  • Literature Cited AboveLegend:   View Online Publication
    • J.C. Hickman, J.C. (editor). 1993. The Jepson Manual: Higher Plants of California. Berkeley: University of California Press. 1400 pp.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
    • Niehaus, T.F. and C.L. Ripper. 1976. Pacific States Wildflowers: Washington, Oregon, California and Adjacent Areas: A Visual Approach Arranged by Color, Form, and Detail. Peterson Field Guide Series, 22. Boston: Houghton Mifflin. xxxii + 432 pp.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Johnson, T. W. 1982. An analysis of pack and saddle stock grazing areas in the Bob Marshall Wilderness. M.Sc.Thesis. Bozeman, MT: Montana State University. 105 p.
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Citation for data on this website:
Long-leaf Evening-primrose — Camissonia subacaulis.  Montana Field Guide.  .  Retrieved on , from