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Montana Field Guides

Swamp verbena - Verbena hastata

Native Species

Global Rank: G5
State Rank: S3S4
(see State Rank Reason below)
C-value: 6

Agency Status


External Links

State Rank Reason (see State Rank above)
Verbena hastata is scattered through southwest, west, and south-central Montana. More current data on population sizes and distributions is needed before warranting it as a Species of Concern.
  • Details on Status Ranking and Review
    Swamp verbena (Verbena hastata) 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

    ScoreD - 6-25 4-km2 grid cells

    Number of Populations

    ScoreC - 21 - 80

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

    ScoreB - Very few (1-3) occurrences with excellent or good viability or ecological integrity

    Environmental Specificity

    ScoreB - Narrow. Specialist or community with key requirements common

    Long-term Trend

    ScoreU - Unknown


    ScoreU - Unknown


    ScoreU - Unknown

    CommentThreats: Unknown/undetermined.

    Intrinsic Vulnerability

    ScoreC - Not intrinsically vulnerable

General Description
Plants: Fibrous-rooted perennials (Lesica 2012), apparently arising from a short caudex (Cronquist et al. 1984). Stems erect, usually simple, hirsute, 20–100 cm (Lesica 2012), or sometimes up to 150 cm (Cronquist et al. 1984).

Leaves: Leaves simple, opposite, hirsute, strigose (Lesica 2012), or smooth to slightly pubescent, rarely scabrous, above, and quite pubescent below, 4-18 cm in length, lanceolate to slightly ovate, serrate or doubly serrate, with the base sometimes arrow-head shaped (hastately 3-lobed), and blade tissue narrowly extending along the petioles (McGregor et al. 1986); petioles (0.5)1-2 cm (Cronquist et al. 1984).

Inflorescence: A flat-topped panicle of narrow spikes, with 1 lance-linear bract subtending each flower; bracts 2–3 mm long (Lesica 2012), inconspicuous and exceeded by the calyx (Cronquist et al. 1984).

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

Flowers June-October (McGregor et al. 1986).

Species Range
Montana Range Range Descriptions


Range Comments
Throughout most of temperate North America (Lesica 2012), from BC to NS, south to CA, NM, TX and FL (McGregor et al. 1986).

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

Observations in Montana Natural Heritage Program Database
Number of Observations: 36

(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)

Thickets, valleys, riparian (Lesica 2012) and damp meadows, seeps, roadside ditches (McGregor et al. 1986).

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

The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus vagans, Bombus rufocinctus, Bombus ternarius, Bombus pensylvanicus, Bombus bimaculatus, Bombus griseocollis, and Bombus impatiens (Thorp et al. 1983, Colla and Dumesh 2010, Williams et al. 2014).

Reproductive Characteristics
Flowers: Slightly irregular, perfect, calyx 2–4 mm long consisting of 5 unequal lobes, strigose; corolla funnelform, blue to violet, slightly irregular, 3–5 mm long (Lesica 2012), rarely white, outer side hairy (McGregor et al. 1986), the petal limb 5–7 mm wide; style ca 1 mm long (Lesica 2012).

Fruit: The 4 reddish-brown nutlets are enclosed in the calyx (which opens at maturity), and are ca 2 mm in length, the top 1/3 with a faintly raised network of lines, the bottom 2/3 with slightly elevated longitudinal lines (McGregor et al. 1986).

(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
    • Colla, S.R. and S. Dumesh. 2010. The bumble bees of southern Ontario: notes on natural history and distribution. Journal of the Entomological Society of Ontario 141:39-68.
    • Cronquist, A., A.H. Holmgren, N.H. Holmgren, J.L. Reveal, and P.K. Holmgren. 1984. Intermountain Flora: Vascular Plants of the Intermountain West, U.S.A. Vol. 4, Subclass Asteridae (except Asteraceae). Bronx, NY: New York Botanical Garden. 573 pp.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
    • McGregor, R.L. (coordinator), T.M. Barkley, R.E. Brooks, and E.K. Schofield (eds). 1986. Flora of the Great Plains: Great Plains Flora Association. Lawrence, KS: Univ. Press Kansas. 1392 pp.
    • Thorp, R.W., D.S. Horning, and L.L. Dunning. 1983. Bumble bees and cuckoo bumble bees of California (Hymenoptera: Apidae). Bulletin of the California Insect Survey 23:1-79.
    • Williams, P., R. Thorp, L. Richardson, and S. Colla. 2014. Bumble Bees of North America. Princeton, NJ: Princeton University Press. 208 p.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Boggs, K. W. 1984. Succession in riparian communities of the lower Yellowstone River, Montana. M.S. Thesis. Montana State University, Bozeman, 107 pp.
    • Britton, N. L. and A. B. Brown. 1913. An Illustrated Flora of the Northern United States, Canada, and the British Possessions. 2nd Edition in 3 Volumes. New York, NY: Charles Scribner's Sons. B13BRI01PAUS.
    • Eggers, M.J.S. 2005. Riparian vegetation of the Montana Yellowstone and cattle grazing impacts thereon. M.Sc. Thesis. Montana State University, Bozeman, MT. 125 p.
    • Jones, W. W. 1901. Preliminary flora of Gallatin County. M.S. Thesis. Bozeman, MT: Montana State College. 78 pp.
    • Sater, S. 2022. The insects of Sevenmile Creek, a pictorial guide to their diversity and ecology. Undergraduate Thesis. Helena, MT: Carroll College. 242 p.
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Swamp verbena — Verbena hastata.  Montana Field Guide.  .  Retrieved on , from