Berteroa incana (Hoary Alyssum)
| Also known as: | Hoary False Madwort |
|---|---|
| Genus: | Berteroa |
| Family: | Brassicaceae (Mustard) |
| Life cycle: | perennial |
| Origin: | Europe |
| Status: |
|
| Habitat: | part shade, sun; dry fields, along roads, disturbed soil |
| Bloom season: | April - October |
| Plant height: | 1 to 3 feet |
| Wetland Indicator Status: | none |
| MN county distribution (click map to enlarge): |  |
| National distribution (click map to enlarge): |  |
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Detailed Information
Flower: 
![[photo of flowers]](/udata/r9ndp23q/white/hoary-alyssum_0608_125845.jpg)
Rounded cluster 1 to 2 inches across at the end of branching stems near the top of the plant. Individual flowers are ¼-inch across and have 4 white petals that are deeply notched to look like 8. There are 6 thick yellowish green stamens in the center. The branching stems elongate as the plant matures, with fruit forming below and flowers just opened at the tip of the stem.
Leaves and stems:
![[photo of leaves]](/udata/r9ndp23q/white/hoary-alyssum-100_3250.jpg)
Fruit:
![[photo of fruit]](/udata/r9ndp23q/pd/berteroa-incana-9.jpg)
Fruit is a round, flat pod ¼ inch long with the stub of a style at the top. They run along the length of the elongated branching stems.
Notes:
Hoary Alyssum was once on the secondary noxious weed list for Minnesota. It is a weedy plant often found in empty lots, on roadsides, degraded fields, railroad rights-of-way, and other sunny locations with dry disturbed soil.
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More photos
Hoary Alyssum plants, single stems
Hoary Alyssum plants, multiple stems from the base
more plants
early basal rosette
a field full of Hoary Alyssum with Hairy Vetch
Hoary Alyssum plants, single stems
Hoary Alyssum plants, multiple stems from the base
more plants
early basal rosette
a field full of Hoary Alyssum with Hairy VetchPhotos by K. Chayka taken at Long Lake Regional Park, Ramsey County. Other photos courtesy Peter M. Dziuk.
Comments
Have you seen this plant in Minnesota, or have any other comments about it?
on: 2010-06-16 22:15:44
We have these EVERYWHERE! Just wanted to put it out there that these cause sore feet in horses if eaten as they are toxic to them. Our Vet told us this today, so you can be sure that I will pull them out before we expand our pasture.
on: 2011-06-13 23:07:02
I see them on the sides of the road here. They are beautiful!
on: 2013-06-29 19:57:17
Hoary alyssum does cause severe metabolic disease in horses ( some seem to be more immune than others). They can develop diarrhea as well as inflamed feet (founder/laminitis), and associated side effects; some have to be euthanized. Most horses will not eat it unless they are food deprived, or it is in their hay. The disease is somwhat dose dependant, as well as individually susceptible. It is a serious toxic weed for horses.
on: 2015-06-13 13:04:36
This popped up in my backyard, which has very sandy soil. It is growing vigorously on the edge of my woodland. I waited for it to flower so I could identify it. I shall now remove the alien invader.
on: 2015-06-21 12:31:18
These are growing alongside the Paul Bunyan State Trail going south out of Bemidji.
on: 2016-08-02 14:58:12
This grows all over the sidewalks and in vacant lots.
on: 2018-06-28 11:32:21
What is the best way to get rid of this?
on: 2019-06-19 16:51:33
Is this something I should pull, or leave well enough alone? It's beautiful
on: 2019-06-23 11:24:16
This plant has just popped up in our field in several large patches this spring and on further inspection ithere are individual plants dispersed all over the field and in the ditches along the county road.
on: 2020-06-08 08:51:30
Just found this in my perennial garden. Guess it's coming out!
on: 2020-07-21 22:20:14
I just plowed under about 2 acres of this weed. It was in a dry, sandy field that I had a deer food plot in last year.
on: 2020-07-22 14:56:30
I just plowed under about 2 acres of this weed. It was in a dry, sandy field that I had a deer food plot in last year.
on: 2022-06-30 16:00:46
MN DNR & USDA lists Hoary Alyssum as an annual or biennial, sometimes short-lived perennial. Plant, of course, is all over. Is here at Lebanon Hills Regional Park.
on: 2024-05-27 17:43:46
Good amount of these in the yard. In the disturbed area where my dog exercises. Will it bother their feet? Or only horses? Should I remove?
on: 2024-05-27 18:15:09
Cori, it's a weed. There is no reason to keep it.