Lobelia siphilitica (Blue Lobelia)

Plant Info
Also known as: Great Blue Lobelia, Blue Cardinal Flower
Family:Lobeliaceae (Lobelia)
Life cycle:perennial
Habitat:part shade, sun; moist fields, along shores
Bloom season:July - October
Plant height:1 to 4 feet
Wetland Indicator Status:GP: OBL MW: OBL NCNE: FACW
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: irregular Flower shape: tubular Cluster type: raceme Cluster type: spike

[photo of flowers] Elongating spike-like raceme of irregular tubular flowers about 1 inch long on a short flower stalk, with a leafy bract at base of the stalk. Color ranges from light blue to bright blue-violet. Flowers have 3 pointed lobes below and 2 smaller lobes above, sometimes erect but usually curved back. In between the upper lobes is a curved style. The lower center lobe has 2 small bumps near the throat, with a spot of white at the top of the bump, and white stripes on the outside of the throat. The calyx holding the flower has long narrow lobes, sometimes with long hairs around the edges. Leafy bracts become smaller as they ascend the stem. The cluster is typically densely packed at the top and a bit looser towards the bottom, with flowers blooming from the bottom up

Leaves and stem: Leaf attachment: alternate Leaf type: simple

[photo of leaves] Leaves are 2 to 6 inches long and up to 2 inches wide, irregularly toothed, hairless or sparsely hairy, pointed at the tip, alternately attached with no leaf stalk. Shape is somewhat variable and may be elliptical, lance-like or only slightly narrowed toward the base. The stem is unbranched, ridged, and may have short hairs scattered along the ridges.

Fruit: Fruit type: capsule/pod

[photo of seed] Fruit is a small 2-chambered capsule, each chamber containing many tiny, oval, semi-translucent golden brown seeds. Seeds are densely covered in a network of fine ridges and many shiny scale-like appendages, almost like shingles. The photo doesn't do them justice. :-)


Blue Lobelia makes a great garden plant—butterflies love it. It is doing quite well in my own poorly drained clay soil in full sun, blooming most of the summer through early fall. The Lobelia genus was once in its own Lobeliaceae family, then was moved to the Campanulaceae (Bellflower) family but is now back in Lobeliaceae. There are 2 varieties, both found in Minnesota. Var. siphilitica is an eastern species where Minnesota is on the western edge of the range; it has leaves typically at least ¾ inch wide, 20 or more flowers in the cluster, and is hairy to varying degrees. Var. ludoviciana is a western species where Minnesota is on the eastern edge of the range; its leaves are less than ¾ inch wide, typically has 6 to 20 flowers, and is mostly hairless.

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More photos

Photos by K. Chayka taken at Long Lake and Rice Creek Regional Parks, Ramsey County. Photos courtesy Peter M. Dziuk taken in Anoka County.


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

Posted by: Pat - Swift County - 9 miles NE of Benson
on: 2010-08-14 20:40:47

Bought a rocky pasture in 2007 with a small stream cutting through it. Have a big patch of this I noticed today. Blooming, and really nice.

Posted by: Mary Beth - Maplewood, Ramsey County
on: 2010-10-05 22:47:17

Blooming on Oct. 4, 2010 in a wet prairie, almost hidden in tall grasses.

Posted by: Lynnette - Welch, Dakota County
on: 2011-08-14 22:40:22

We live on the bluff overlooking Prairie Island, between Hastings & Red Wing. Our property has sandy, well-drained soil, and yet we have a good stand of blue lobelia growing here in the woods. It finished blooming in August 2011.

Posted by: Rick - Cass Co. Thunder Lake
on: 2011-08-21 16:54:06

Blue Lobelia currently blooming along the lakeshore among Joe-Pye, cattail, and various grasses.

Posted by: Carol - Eden Prairie
on: 2011-09-16 15:25:25

Photographed this flower today on a walk along Purgatory Creek.

Posted by: Gene - Evansville
on: 2013-09-30 16:47:06

I found a couple one foot high single blossomed stems growing a few feet from the lake shoreline in damp soil on a path in heavy clay soil 9/30/2013.

Posted by: Jonathan - Edina, MN
on: 2014-09-16 13:59:19

Several in bloom beside the wetland portion of my prairie planting

Posted by: Linda - Lebanon Hills Park, Eagan
on: 2015-05-29 01:58:57

It was a delight to see this blooming on the shore of O'Brien Lake in Lebanon Hills Park. Only one I've ever seen in the park.

Posted by: Harold - Fairfax in Renville County
on: 2015-09-21 22:53:39

I first found blue lobelia in Grundmeyer Wildlife Management Area west of Gibbon. Later I found some at Fort Ridgely State Park next to a small lake in a prairie area. I went on a tour of Seminary Fen Scientific Natural Area (SNA) near Chaska and they were blooming there too.

Posted by: Kenny h - Rural Mower County
on: 2017-08-17 22:07:58

Found 5 of these treasures in the corner of an old cow pasture...saw them on a drive by...stopped and took photos...lots of other native good stuff there...these were the closest to being blue that I have ever seen.

Posted by: Tom B - Northeast Freeborn County
on: 2017-08-27 11:17:23

I found ramdom plants in half bloom growing in a third year WREP planting. They do not compete very well with canada thistles.

Posted by: Mandy S - Maplewood
on: 2017-09-02 08:16:39

We've found several growing along the shoreline of our ponds. They started blooming in August.

Posted by: Peg S - Found in old pasture in Western WI
on: 2017-09-18 14:14:20

This posture had been treated with Roundup then planted with native prairie species. Lobelia was not one of the forms we planted! but seed bank survived. Beautiful!

Posted by: Nancy Carroll - Eastern Becker County, MN
on: 2018-08-04 11:18:46

Found it on the bank of a beaver pond.

Posted by: Phil J Gerla - Ozawindib Lake, Itasca State Park
on: 2018-08-21 22:07:33

Together with Gentiana andrewsii on a sandy shore of the lake.

Posted by: Andy Frank - Winona County
on: 2018-09-03 12:03:09

Found beautiful clumps of these on Camp Rd. today near E. Burns Valley Rd. between the road and pasture fence in a grassy wet ditch, near Burns Valley Creek. Lovely!

Posted by: Edward A Pfannkoch - Chatfield
on: 2019-08-24 08:21:28

I found a clump of blue lobelia growing in our pasture and alongside it is one or more similar plants that have pure white flowers. Is the "alba" version native to our area?

Posted by: K. Chayka
on: 2019-08-24 08:31:38

Edward, it is not uncommon to occasionally have a white-flowered specimen in plants that normally have blue, purple or pink flowers. It is a natural variation, not a different (sub)species or var and may or may not be hereditary. We've seen it many times in many different species.

Posted by: luciearl - owatonna
on: 2019-08-29 06:04:58

Went to view a shoreline restoration project on Gull Lake. This was a new one for me and delighted to find it is native. Beautiful and thriving along with many other native plants.

Posted by: Marisa Newton - Thief River Falls // Pennington County
on: 2019-08-29 14:40:27

Found August 29, 2019 in full bloom. Approximately 1.5 - 2ft tall growing in the rain garden of the Red Lake Watershed office building. Beautiful contrast w/ all the coneflower // golden rod // black eyed susans! Planted in 2011.

Posted by: Jeff - SAINT PAUL
on: 2019-09-01 16:20:09

Blooming in Lebanon Hills Park, Dakota County. 9/1/18

Posted by: Janice Tokarczyk - Sturgeon Lake
on: 2019-09-03 17:21:46

Three years ago I planted 4 acres of Minnesota Native pollinator m8x from Albert Lea Seed Co. It has been quite wet this year, and I have a lot of Lobelia siphilitica in the habitat, particularly in the less well drained areas. The bees love it.

Posted by: Jill Mackenthun - In country between Brownton, Glencoe and Hutchinson MN
on: 2019-09-14 14:06:17

Mowing 2 weeks ago and found 2.5 foot plant along barn, about 6 feet from my Butterfly garden. Tried growing Cardinal Lobelia years ago with no luck. The Blue Lobelia I found must have been a gift from the birds. I marked and flagged it so it wouldn't get pulled. LOVE IT!

Posted by: Roger Hintze - Shoreview in Ramsey County
on: 2020-08-16 12:57:20

Great Blue Lobelia - began flowering in my yard on August 15. I planted it in my perennial bed many years ago. The bumblebees love it. It seeds itself quite generously.

Posted by: Daniel Jones - Dundas, Rice County
on: 2020-08-16 15:44:05

Small but robust patch at edge of the Dundas dog park, in full bloom in a wet transitional area between a cattail slough and a gentle rise to the southeast. Associated with blue vervain, swamp milkweed, impatiens/touch-me-not and several sedge species.

Posted by: Andy Lowe - Wisel Creek, Fillmore County
on: 2021-08-10 22:48:38

Saw the most brilliant blue/violet lobelia along Wisel Creek while fishing. New flower for me!

Posted by: Ron Johannsen - Trenton Lake
on: 2021-08-12 19:28:52

Many blooming now very showy and attracts one's eyes instantly.

Posted by: Harvey D Tjader - Bemidji
on: 2021-08-19 14:14:58

Growing along the shore of Lake Bemidji in Diamond Point Park

Posted by: Laura T Hunter - Hubbard County
on: 2021-08-31 12:01:27

Seen blooming off shoreline of Big Stoney Lake South of Dorset

Posted by: Kari Adams - Morris, MN: Stevens County
on: 2021-09-04 22:09:01

Blooming in a wet area near willows at the Morris Wetland Management's Wildlife Trail

Posted by: Christine - Clearwater MN
on: 2022-09-02 15:16:55

A large patch of approx 40 stems growing by the edge of Long Lake on our property this year.

Posted by: Ben - Welcome, MN
on: 2022-09-12 09:30:51

Have several acres on my farm in full bloom this weekend.

Posted by: Curtis - Eden Prairie
on: 2022-09-22 18:02:45

There are a few blooming along the Purgatory Creek trail in Eden Prairie. There would have been more but the trail maintenance crew mowed them down. I've been watching bumblebees gather nectar from these, and the bees tend to crawl around the outside of the flower rather than stick their heads inside. They seem to be gathering the nectar through the gaps between the petals. I don't know how that affects pollination because they don't come in contact with the pistil hanging above the flower opening. Maybe smaller insects do the actual pollinating? I don't know.

Posted by: K Chayka
on: 2022-09-23 16:43:53

Curtis, bumblebees are the only bees strong enough to pry open the flower, so smaller bees aren't effective pollinators. Sometimes, bees will make holes at the base of a flower to get to nectar they otherwise might have a hard time reaching. I know this happens with red columbine and other species.

Posted by: Wendy Stone - Grant
on: 2023-09-20 11:34:25

A single plant showed up in our nursery plot of Bee Balm this year. We do drip irrigation in this east-facing plot, the soil is refreshed with compost yearly and compost tea monthly. I'm hoping it propagates on its own. The bumblebees are all over it now that the monarda is finished.

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