Polemonium lacustre (Great Lakes Jacob's Ladder)

Plant Info
Also known as:
Family:Polemoniaceae (Phlox)
Life cycle:perennial
  • State Endangered
Habitat:part shade, shade, sun; conifer swamps
Bloom season:June - July
Plant height:to 40 inches
Wetland Indicator Status:GP: none MW: FACW NCNE: none
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

Pick an image for a larger view. See the glossary for icon descriptions.

Detailed Information

Flower: Flower shape: 5-petals Flower shape: bell Cluster type: panicle Cluster type: raceme

[photo of flowers] Compact clusters of stalked flowers at the top of the stem and arising from upper leaf axils, the clusters at the tips of long, slender stalks covered in sticky hairs. Flowers are blue to violet, about 2/3 inch wide, bell shaped with 5 spreading lance to egg-shaped petals that are a bit ruffled around the edges and are longer than the floral tube. The throat of the tube is creamy white with dark lines; extending well out from the center is a single white style with a 3-parted stigma at the tip, the tips purple or edged with purple, and 5 pale-tipped, white stamens that are shorter than the style.

[photo of calyx] The calyx surrounding the base of the flower has 5 lance-oblong lobes that are 3 to 4 times longer than the calyx tube, the outer surface and flower stalk are covered with spreading, sticky hairs.

Leaves and stems: Leaf attachment: alternate Leaf attachment: basal Leaf type: compound

[photo of basal leaves] Most leaves are not associated with a flowering stem but emerge nearby from short stems on underground rhizomes. These leaves and the lowest stem leaves are pinnately compound with 3 to 27 leaflets, up to 6 inches long with a long stalk. Stalks have narrow edging and may appear grooved. Leaflets are lance-linear, ½ to 1½ inches long, toothless and hairless.

[photo of stem leaves] Stem leaves are few, alternate, becoming smaller with shorter stalks as they ascend. Flowering stems are long and rather slender, mostly smooth in the lower plant but with dense, sticky hairs towards the tip and on the cluster and flower stalks.

Fruit: Fruit type: capsule/pod

Fruit is a small capsule containing up to 10 tiny, dark brown seeds.


Polemonium lacustre was previously considered a subspecies of Polemonium occidentale (subsp. lacustre), but recent genetic testing found it to be distinct enough from the more common subsp. occidentalis of the Rocky Mountains to warrant being split into a separate species. It requires wet swamps associated with white cedar, black spruce and tamarack. In spite of nearly 50 years of extensive survey of what appears to be similar habitat throughout the upper Great Lakes, it is severely restricted to just a handful of locations. According to the DNR, it was first discovered in Minnesota in 1944 and today is currently known from just a handful of separate populations in two Minnesota counties plus one county in Wisconsin. In both states it is ranked as Critically Imperiled and so listed as Endangered, though it is not presently Federally listed.

Please visit our sponsors

  • Minnesota Goose Garden

Native Plant Nurseries, Restoration and Landscaping Services ↓

Map of native plant resources in the upper midwest

  • Morning Sky Greenery - Native Prairie Plants
  • Natural Shore Technologies - Using science to improve land and water
  • Minnesota Native Landscapes - Your Ecological Problem Solvers
  • Spangle Creek Labs - Native orchids, lab propagated
  • Prairie Restorations - Bringing people together with the land

More photos

Photos by K. Chayka taken Itasca County. Photos by Peter M. Dziuk taken in Itasca and St. Louis counties. Photos by John Thayer taken in Itasca County.


Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: Christopher - Cannon Valley Trail near Welch
on: 2020-05-25 18:17:40

I saw a fair number of these plants along the bike trail. I took several photos in order to identify them later. I was surprised that they are rare and found near spruce and hemlock swamps. there is nothing like that along the CVT. I would be happy to provide photos. Western Jacobs Ladder

Posted by: K. Chayka
on: 2020-05-25 18:57:29

Christopher, it is pretty unlikely you saw the rare Polemonium occidentale in the Cannon River valley; I assume it was P. reptans, spreading Jacob's ladder, which is a woodland species and quite common in that area.

Posted by: Jeanice Moffatt - St. Louis County
on: 2020-06-08 20:42:55

Would we have seen these today in Sax-Zim bog? We saw some along one of he roads and this is a close as I can come to identifying them. Thanks!

Post a comment

Note: All comments are moderated before posting to keep the riff-raff out. An email address is required, but will not be posted—it will only be used for information exchange between the 2 of us (if needed) and will never be given to a 3rd party without your express permission.

For info on subjects other than plant identification (gardening, invasive species control, edible plants, etc.), please check the links and invasive species pages for additional resources.


Note: Comments or information about plants outside of Minnesota and neighboring states may not be posted because Id like to keep the focus of this web site centered on Minnesota. Thanks for your understanding.