Solanum rostratum (Buffalo Bur Nightshade)

Plant Info
Also known as: Kansas Thistle
Family:Solanaceae (Potato)
Life cycle:annual
Origin:Southwest U.S.
  • Weedy
Habitat:sun; dry, along roads, waste areas
Bloom season:June - September
Plant height:1 to 3 feet

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Detailed Information

Flower: Flower shape: 5-petals Cluster type: raceme

[photo of flowers] Flowers are in a raceme that grows up to 6 inches long; flowers bloom from the bottom up. Individual flowers are about 1 inch across with 5 bright yellow fused petals with crinkled or wavy edges. There are 5 tubular stamens and a long curved style in the center. The bract is spiny. One plant has a few to several racemes on its many branches.

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

[photo of leaves] Leaves are up to 6 inches long and 5 inches wide, with irregular and deep rounded lobes. There are yellow spines along the major veins on both sides of the leaf, and on the leaf stem. The underside is hairy.

[photo of stem] The main stem is covered in sharp yellow spines.


[photo of fruit] Fruit is a many-seeded berry encased in a spiny covering,


This is one mean plant—every part of it is covered in sharp spines. It's kind of interesting to look at, but touch at your own risk! I've read different opinions of where this plant originates, but the consensus seems to be it is native to the U.S., but not to the Upper Midwest.

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More photos

Photos taken at the Northwest Quadrant construction site, Old Highway 8, New Brighton, MN August 2008


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

Posted by: M. R. - Eden Prairie
on: 2009-07-16 19:25:38

I removed a great deal of rock that had been under the deck for years. Before I've figured out my plan for the space and what would grow best, two of these have appeared on their own and are quite pretty. Mine have only grown to about 6" tall thus far, but they have the yellow flowers and the thorns all over. I had never seen them before, so found this site in trying to identify what they were.

Posted by: clyde - menahga
on: 2009-07-25 11:36:44

I found a single Buffalo Bur Nightshade plant growing under my birdfeeder. Thanks to your website I was able to identify it.

Posted by: Casey - Saint Paul
on: 2011-06-28 15:31:15

I have rock surrounding my home and one of these has managed to grow next to my front steps sprouting out from the rock. It's about 16 inches. I was trying to identify it and found this website. Thanks

Posted by: Steph - Royalton MN
on: 2012-08-08 10:40:04

We had one of these growing just off the edge of our patio. I kept it around for a while to see what it would grow into. Then googled it and seen it's not a great plant to have around. I think it came home with my hubby from working in ND.

Posted by: Chris - Mankato
on: 2013-08-18 20:24:26

This plant appeared and flowered after we trimmed out dead cranberries. I'm glad there's only one! I really appreciate having a website like yours for help with identifying wildflowers.

Posted by: David - Winona Co.
on: 2014-08-04 15:23:52

I found it growing in disturbed soil under the bird feeder at the Whitewater WMA. Waited for the bloom now I will kill it.

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