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

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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.

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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!

Posted by: Bruce J Hall - St. Cloud
on: 2018-06-27 20:26:09

Along wetland margin on east side of CR 39 just north of MN. hwy. 113 in Becker Cty, near Long Lost Lake. 2016-2018

Posted by: Cynthia - Gnesen Township, N of Duluth
on: 2018-07-26 15:11:24

Have seen one plant in a bog on our land.

Posted by: John Lawrey - Fire Road 172 East of Isabella
on: 2020-06-08 20:30:09

Very plentiful in the bogs and on the lakeshores of this area. Had good company with Bog Laurel and Pitcher Plants. There is a bogwalk on Divide Lake where you can also find Sundew.

Posted by: Viktoria Krikorian - Snowbank Lake (Lake Co)
on: 2020-06-10 19:19:38

Found it in one of the bays on 6/9/2020 while kayaking.

Posted by: Sharon - Woodbury
on: 2022-05-30 09:42:44

There are many of these in bloom along the boardwalk at Tamarack Nature Preserve. I've seen these before at the Quaking Bog at Theodore Wirth Park in Minneapolis, but never close enough to notice their interesting leaves.

Posted by: Joe Walton - Eagan, MN
on: 2024-05-16 02:04:33

We saw it in a Tamarack Swamp in Lebanon Hills Regional Park just west of Holland Lake.

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