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Montana Field Guides

Lewis' Mock Orange - Philadelphus lewisii
Other Names:  Philadelphus trichothecus

Native Species

Global Rank: G5
State Rank: S5
C-value: 4

Agency Status


External Links

General Description
PLANTS: Shrub with exfoliating bark, 1–3 m. Twigs reddish, glabrous. Source: Lesica et al. 2012

LEAVES: Leaves opposite, short-petiolate, elliptic, the blades 2–6 cm long with mostly entire margins, glabrous to sparsely hairy. Source: Lesica et al. 2012

INFLORESCENCE: A several-flowered, terminal raceme on lateral branches. Flowers bisexual, regular, fragrant; calyx 4-lobed, forming a hypanthium; petals 4, separate, white, ovate, 1–2 cm long; stamens 20 to 40; stigmas 4; ovary partly inferior. Fruit an elliptic, capsule, 6–10 mm long, 4-loculed; seeds numerous. Source: Lesica et al. 2012

Diagnostic Characteristics
Philadelphus lewisii exhibits a great deal of morphological variation across its range in western Canada and the western U.S. Philadephus trichothecus was considered an intermediary form in Montana, but later given species recognition by S.Y. Hu. That came to pass in 2016 when Freeman lumped it with Philadelphus lewisii, considering it a synonym (Freeman in Flora of North America 2016).

Species Range

Range Comments
British Columbia, Alberta in Canada south to California, Idaho, and Montana in the United States (Lesica et al. 2012).

Observations in Montana Natural Heritage Program Database
Number of Observations: 274

(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)

Dry, rocky slopes in grasslands and open forest in the valleys and montane zones of Montana (Lesica et al. 2012).

The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus impatiens (Colla and Dumesh 2010).

  • 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.
    • Flora of North America Editorial Committee. 2016. Flora of North America north of Mexico. Vol. 16. Oxford University Press, New York.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Cope, M.G. 1992. Distribution, habitat selection and survival of transplanted Columbian Sharp-tailed Grouse (Tympanuchus phasianellus columbianus) in the Tobacco Valley, Montana. M.Sc. Thesis. Bozeman, Montana: Montana State University. 60 p.
    • Fogelsong, M.L. 1974. Effects of fluorides on Peromyscus maniculatus in Glacier National Park. M.Sc. Thesis. Bozeman, Montana: Montana State University. 52 p.
    • Gaffney, W.S. 1941. The effects of winter elk browsing, South Fork of the Flathead River, Montana. Journal of Wildlife Management 5(4):427-453.
    • Jones, W. W. 1901. Preliminary flora of Gallatin County. M.S. Thesis. Bozeman, MT: Montana State College. 78 pp.
    • Kitchen, K.A. 2010. The influence of Douglas-fir and Rocky Mountain juniper on Wyoming and mountain big sagebrush cover in southwest Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 87 p.
    • Martinka, R.R. 1970. Structural characteristics and ecological relationships of male blue grouse (Dendragapus obscurus (Say)) territories in southwestern Montana. Ph.D Dissertation. Bozeman, MT: Montana State University. 73 p.
    • Morris, M.S. and J.E. Schwartz. 1957. Mule deer and elk food habits on the National Bison Range. Journal of Wildlife Management 21(2):189-193.
    • Steerey, W. F. 1979. Distribution, range use and population characteristics of Mule Deer associated with the Schafer Creek winter range, Bridger Mountains, Montana. M.Sc. Thesis. Bozeman, Montana: Montana State University. 119 p.
  • Web Search Engines for Articles on "Lewis' Mock Orange"
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Citation for data on this website:
Lewis' Mock Orange — Philadelphus lewisii.  Montana Field Guide.  .  Retrieved on , from