Menyanthes trifoliata (Buckbean)

Plant Info
Also known as: Bog Bean, Marsh Trefoil, Water Shamrock
Family:Menyanthaceae (Buckbean)
Life cycle:perennial
Habitat:part shade, sun; bogs, wetlands, along shores, shallow water
Bloom season:April - July
Plant height:4 to 12 inches
Wetland Indicator Status:GP: OBL MW: OBL NCNE: OBL
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: tubular Cluster type: raceme

[photo of flowers] Showing raceme of 10 to 20 ½-inch white trumpet-like flowers on a stout, smooth, green stem arising from the rootstock. The 5-petalled flowers are fused into a short tubular throat, petals flaring back revealing wiry bearded hairs on the inner surface. 5 white stamens with dark reddish to black tips are attached to the tube wall, alternating with the petals; a long slender style emerges from the throat of the tube. Flowers have a stout stalk and bloom from the bottom up; sometimes flowers are tinged purple.

Leaves and stem: Leaf attachment: basal Leaf type: palmate

[photo of leaves] Leaves are palmately compound in 3s, attached at the rootstock, sometimes several inches away from a flowering stem. At blooming time leaflets are 1½ to 2½ inches long and to 1 inch wide, becoming larger later in the season. Leaflets are oval to oblong with smooth, sometimes wavy edges. Leaf stem is smooth, sheathed, and shorter than the flowering stem.


Like a woodland spring ephemeral, the bloom period for Buckbean is brief and then gone for the season. I first ran into this at Cedar Creek Natural History Center in 2004 (was not happy with the images) but not again until this last season (2010), though it's not like I spend all my time in the swamps. This species is offered in the aquatic garden trade and I had hoped to catch it in bloom at Baldwin Lake Perenniels in Lino Lakes—still I missed it in recent years. Finally this season out looking for long-bracted orchid, Dactylorhiza viridis, we found all the buckbean we should ever want. While garden images will serve for ID purposes, it's nothing like finding it in situ.

Please visit our sponsors

  • Wild Ones Twin Cities Chapter

Where to buy native seed and plants ↓

Map of native plant purveyors in the upper midwest

  • Morning Sky Greenery - Native Prairie Plants
  • Minnesota Native Landscapes - Your Ecological Problem Solvers
  • Natural Shore Technologies - Using science to improve land and water
  • Itasca Ladyslipper Farm - Native orchids, container grown
  • Prairie Restorations - Bringing people together with the land

More photos

Photos by K. Chayka and Peter M. Dziuk taken in Aitkin County


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

Posted by: Katherine - Finland
on: 2013-06-13 18:07:39

Grows in a bog behind our property on the Lax Lake Rd., just outside Finland.

Posted by: Jean - Stewart Lake boat landing nw of 2harbors
on: 2014-06-08 16:47:50

Many plants left side of dock

Posted by: Beth - Spring Lake
on: 2015-05-26 21:50:40

We have it in a lovely little bog near our home!

Posted by: Kathy - Theo Wirth Park-Quaking Bog, Minneapolis
on: 2016-05-15 22:53:59

Found two clumps of these in the Quaking Bog at Theo Wirth Park in Minneapolis today (Sun, May 15, 2016, around 5pm).

Posted by: Marsha D - Bemidji
on: 2017-05-20 15:57:30

Several plants found at Sundew Pond at Lake Bemidji State Park in mid-May. (5/19/17) This is a lovely wildflower, although it took some time to identify it!

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.