Douglas's Hawthorn - Crataegus douglasii
Crataegus columbiana [misapplied], Crataegus okennonii, Crataegus rivularis, Crataegus columbiana
MNPS Threat Rank
Shrubs 4–6 m high. Stems tan when young becoming gray; thorns 15–25 mm long, straight to curved. Leaf blades obovate, 3–7 cm long, twice serrate and shallowly lobed above, appressed-hairy, glabrous and glaucous beneath. Inflorescence 5- to 25-flowered, glabrous. Flowers: hypanthium glabrous externally; sepals 2–4 mm long; petals 5–8 mm long: stamens 10; styles 3 or 4. Pome 6–12 mm wide, purple to black, glabrous at maturity (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
AK to SK, south to CA, ID, WY and SD (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus vagans
, Bombus auricomus
, Bombus melanopygus
, Bombus mixtus
, Bombus nevadensis
, Bombus pensylvanicus
, Bombus bimaculatus
, Bombus griseocollis
, and Bombus impatiens
(Macior 1968, Thorp et al. 1983, 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.
- Macior, L.M. 1968. Bombus (Hymenoptera, Apidae) queen foraging in relation to vernal pollination in Wisconsin. Ecology 49:20-25.
- 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.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Aldrich, D. F. 1978. Overwintering, springtime development and migration of some Aphidea, including Myzus persicae of Northwestern Montana. M.Sc. Thesis. Bozeman, Montana: Montana State University. 112 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.
- Jones, W. W. 1901. Preliminary flora of Gallatin County. M.S. Thesis. Bozeman, MT: Montana State College. 78 pp.
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Seipel, T.F. 2006. Plant species diversity in the sagebrush steppe of Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 87 p.