Hibiscus trionum (Flower of an Hour): Minnesota Wildflowers

Hibiscus trionum (Flower of an Hour)

Plant Info
Also known as:
Genus:	Hibiscus
Family:	Malvaceae (Mallow)
Life cycle:	annual
Origin:	Europe
Status:	Noxious Weed
Habitat:	sun; fields, roadsides, waste areas
Bloom season:	July - September
Plant height:	4 to 24 inches
USDA PLANTS database:	Minnesota county distribution map

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Detailed Information

Flower:

Flowers are 2 to 2½ inches across with 5 round, overlapping pale yellow petals, deep purple at the base. In the center are many bright orange tipped stamens and a stigma rising up in the center with 5 deep red, fuzzy round branches at the tip. Behind the flower are 5 translucient sepals, starkly veined with stiff hairs on vein ridges. Up to 12 narrow, spreading, hairy bracts sit below. Flowers arise on hairy stalks from leaf axils in the upper part of the plant

Leaves and stem:

Leaves are up to 3 inches long and 2 inches wide, palmately compound mostly in 3's, each leaflet with rounded lobes and the end leaflet largest. Stems are branched at base, sparsely wooly, semi-erect or sprawling.

Notes:

Flower of an Hour is an increasing field/garden/roadside pest in Minnesota, the flowers are quite beautiful, lasting only briefly in the day.

Where to buy native seed and plants

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Map of native plant purveyors in the upper midwest

More photos

Flower of an Hour plant

Photos courtesy Peter M. Dziuk, taken in cultivated fields in Anoka and Dakota Counties

Comments

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

Posted by: Theresa in my flower bed
on: 2010-06-30 10:49:07

I purchased a package of wildflowers 2 years ago and these were in there. I left them grow and they come back every year. My father-in-law just pulled all of them out though.

Posted by: K. Chayka
on: 2010-06-30 16:41:30

That is a continuing problem--invasive species are still sold in seed packets (mail order, especially) and in garden centers. Most people don't even realize they're buying weeds.

Posted by: Kelly in Shakopee
on: 2011-07-06 14:29:59

I have no idea where these have come from. I LOVE them I look forward to each flower when it blooms. It is in a contained rock bed and so it hasn't spread very far in 5 years. Actually, I am intentionally spreading it through out th rocks.. is this bad?

Posted by: K. Chayka
on: 2011-07-06 18:12:36

Kelly, I just want to comment on your first statement: "I have no idea where these have come from". See, this is the problem. They escaped from somewhere else and landed in your yard. Don't be fooled into thinking they are not escaping from your yard and landing somewhere else, because that is what invasives do.

You may think you have them contained but you don't really. Seed is transported elsewhere by wind, water and critters and unless you keep them indoors they will end up in the landscape outside of your yard. They are a noxious weed. Pretty, maybe, but a weed nonetheless. There are so many wonderful native species you might have in your garden. Why not plant some of them instead?

Posted by: John in Cottage Grove (Washington County)
on: 2011-07-31 13:46:40

I seeded a wild flower mix along a transition between my lawn and a 1 acre pasture 5 years ago. I tilled and planted pumpkins in that field the last 2 years. This year I tilled and reseeded with a high purity Clover-Timothy Blend. This species is now populated throughout this new clover-timothy field, but it did not come from the new seed, as this is the only field with this species between the 2 fields I reseeded. I was not concerned but after reading above,I hope it will be crowded out as I mow the pasture 2-3 times per season for weed control.

Posted by: Bonnie in Cannon Falls
on: 2011-09-03 17:39:03

We live next to the woods and have a lot of birds and critters in the area. I am guessing that a bird or a bunny dropped a couple of seeds in my small watermelon patch or it somehow got into the watermelon seed pack. They were allowed to grow because at first, their leaves looked similar to baby watermelon, and then when they surprised me with their beautiful little flower, I let them live. Quite pretty actually. Living here for years, we gave up struggling to completely keep out the invasive wildflowers from the woods. Life's too short.