Solanum Species, Buffalo Bur, Buffalobur Nightshade, Colorado Bur, Kansas Thistle, Mexican Thistle

Solanum angustifolium

Family: Solanaceae (so-lan-AY-see-ee) (Info)
Genus: Solanum (so-LAN-num) (Info)
Species: angustifolium (an-gus-tee-FOH-lee-um) (Info)
Synonym:Solanum rostratum



Water Requirements:

Unknown - Tell us

Sun Exposure:

Full Sun

Sun to Partial Shade




Foliage Color:




12-18 in. (30-45 cm)


12-15 in. (30-38 cm)

15-18 in. (38-45 cm)

18-24 in. (45-60 cm)


Not Applicable

Where to Grow:

Unknown - Tell us


Plant has spines or sharp edges; use extreme caution when handling

Bloom Color:

Bright Yellow

Bloom Characteristics:

Unknown - Tell us

Bloom Size:

Unknown - Tell us

Bloom Time:

Late Spring/Early Summer

Mid Summer

Late Summer/Early Fall

Mid Fall

Late Fall/Early Winter

Other details:

May be a noxious weed or invasive

Soil pH requirements:

Unknown - Tell us

Patent Information:


Propagation Methods:

From seed; direct sow after last frost

Seed Collecting:

Allow pods to dry on plant; break open to collect seeds

Wear gloves to protect hands when handling seeds


This plant is said to grow outdoors in the following regions:

Fort Smith, Arkansas

Banning, California

Stockton, California

Aurora, Colorado(2 reports)

Golden, Colorado

Lamar, Colorado

Springfield, Colorado

Yale, Iowa

Oakland, Maryland

Sedalia, Missouri

Campton, New Hampshire

Whiting, New Jersey

Elephant Butte, New Mexico

Roswell, New Mexico

Dayton, Ohio

Dover, Pennsylvania

Sugarloaf, Pennsylvania

Copperas Cove, Texas

De Leon, Texas

Kerrville, Texas

North Richland Hills, Texas

Richmond, Texas

San Antonio, Texas

Eden, Vermont

Walkerton, Virginia

Alderwood Manor, Washington

Brier, Washington

show all

Gardeners' Notes:


On Mar 11, 2018, Oceanpeg from Whiting, NJ wrote:

Last year, 2017, the Buffalo Bur popped up on its own, here in NJ, in June. We have those in the ground garbage cans in our senior citizens complex. Our senior village maintenance department replaced the old ones with newer ones, and, when doing so, had to dig the hole deeper. After doing so, and bringing up stoney and sandy light brown soil, the Buffalo Bur popped up on its own, near our garbage cans. We had to cut the Buffalo Bur down in order to access our garbage cans when it became larger. It really looked like a nice plant until the thorns and the bur's appeared on the stem of the plant. We're hoping that we aren't going to have to deal with it again this year. Some of my out of state friends who delt with it, themselves, suggesting using a mixture of vinegar and salt to get rid of t... read more


On Jun 18, 2015, kla7238 from Pittsburgh, PA wrote:

I have dug up some of my yard to create a new bed last summer. I dumped the poor, rocky dirt along the side of my house. This year, while weeding, I came across a plant that from far away, I thought was a volunteer tomato plant. Then I saw the thorns, lots of them, very long and vicious looking. After searching the internet, I found out it was Buffalobur nightshade or Solanum rostratum. I have no idea how it got there, I live in Southwestern Pennsylvania. It sounds truly evil. How do I get rid of it so it doesn't come back?
This is not the first time I have found a plant in my garden that doesn't belong there. 3 years ago I found, what I thought was a gladiola, until it bloomed. It was a tropical flower, comes back every year, even after extremely cold winters. Wish I could reme... read more


On Jun 3, 2015, rsb148 from Nanticoke, PA wrote:

Pretty plant that closely resembles watermelon when young. Closer inspection soon reveals the nasty spines. On my property, it's concentrated near bird feeders and seeds may have hitch-hiked a ride in here with last winters black oil sunflowers seeds. Not good for bare foot areas, use gloves to pull.


On Sep 7, 2014, Chillybean from (Zone 5a) wrote:

I first noticed this plant some years ago; learned it was toxic and the first one I pulled gave me a terrible rash. I wore gloves after that.

Because I rarely wear gloves walking around my little wannabe prairie, this year, I've just been pulling them up by hand. Yet no longer do I get that rash. Interesting.

You may wonder why I give this plant a positive when I yank it up any time I come across one. It is native to the US, so belongs here. Today, I found some treasures in my wannabe prairie, but also found one of these Buffalo Burs in full bloom. That, I had never seen before. It has a lovely yellow flower. I took a picture before the yank.

What I found interesting is that this is part of the potato family and the original host for... read more


On Aug 25, 2013, TeeTop from White City, OR wrote:

This plant can be a pain when it comes to bike tires.
Living in White City, Oregon, where it is a troubling weed the county likes to weed whack.
A beautiful plant that is very problematic in our area, coupled with the Goats Heads a head ache for bike riders.


On Jul 19, 2012, loggah from Campton, NH (Zone 4b) wrote:

I was very surprised to find this plant On the edge of the lawn outside one of my flower beds. No idea where it came from. It's not listed in the Eastern Edition of Peterson's Wildflowers of Northeastern/North-central North America, but I did find it in the Southwestern and Texas edition. Sure didn't expect this plant to show up in New Hampshire!


On Jun 14, 2012, StephanieRoque from West Carrollton City, OH wrote:

everything I have read about this "weed" is negative. I have one in my garden and was curious about it so I posted it on facebook and one of my friends identified it. I live in Ohio, so I am surprised to see it is mostly found in the southwestern United States! I planted watermelons in my garden this year, (a first,) and the leaves look IDENTICAL to that of the watermelon, except for the yellow flowers and the thorns, I would have left it there thinking it WAS a watermelon! needless to say, I pulled it. (carefully) but I am trying to figure how this thing got in my watermelon seed pack I bought from LOWES. My only conclusion is the package says it is a "product of Mexico," so seeing as where it is Native, I assume this was an accident..


On Dec 1, 2009, texasflora_com from De Leon, TX (Zone 8a) wrote:

I rarely give a negative to any plant but I just can't find any redeeming qualities for this evil plant. We always called them bull nettles/stinging nettles around here, but those are actually different plants and are very edible and nutritious. The buffalobur/cocklebur has barbs on its thorns like a fish hook. I think this monster is the reason behind the dinosaur extinction.


On Aug 4, 2009, chrisrglenn from Lynnwood, WA wrote:

Note: Audubon Society says this plant is "Highly Toxic" (see below)

My wife and I first noticed this plant in our Lynnwood, Washington yard about 3 or 4 days ago. I took a picture of it, because it was so unusual looking. I sent the picture to a friend. In discussing it, I decided to look it up in my "The Audubon Society "Field Guide to North America, Wildflowers, Western Region." Color plate #210, informational text, page 790.
Further research lead me to this web page. The only reason I am commenting is that the Aubudon Society warned highly toxic and some of the people who commented on this web page seemed to have an interest in cultivating this invasive/toxic plant. (And I intend to cremate this plant, but not in a BBQ that I cook in! This thing just showed up-hav... read more


On Sep 15, 2008, Arden2 from Olympia, WA wrote:

This plant came up in my Western Wa, garden. Saw the bright yellow flowers among the petunias and reached in to identify. Very prickly. Pulled and pressed. The flowers helped with the ID as a solanum. Its a Class A weed here, but has not become established according to the Weed Board.


On Sep 2, 2008, Joesgirl from Stockton, CA wrote:

This plant volunteered in my flowerbed. After doing some research and realizing I had a monster on my hands, I carefully pulled it up and had my husband insinerate it in the BBQ grill before it could seed.


On Oct 29, 2007, marwood0 from Golden, CO (Zone 5b) wrote:

Attractive flowers and foliage, fantastic thorns, can control easily in very dry areas. Attracts butterflies and potato bugs. Very bad for pasture / grazing land, but nice addition to a garden or to use as a deterent to foot traffic. Pull in the fall before it seeds. Wear gloves.


On Sep 3, 2005, trois from Santa Fe, TX (Zone 9b) wrote:

While a pretty flowering plant, it is the most invasive plant I have seen. Large farms can become worthless in just a couple of years with out constant ploughing. My experience was in Southwestern Oklahoma.


On Aug 15, 2004, BobAndrews from Haines, AK (Zone 4a) wrote:

I found a single solanum rostratum growing in Haines, Alaska in my manure pile in mid-July (2004) I have let it grow, as I have never seen such a plant before. Will probably pull it out before it seeds.


On Jun 15, 2004, Mimi_A from Chico, CA wrote:

I have never seen a plant with thorns on the top of the leaves (big thorns, at that)! Two of these came up in my flower garden in Chico, California, this spring and I let them grow until the seed pods (resembling gooseberries) formed. None of our nurseries recognized the plant, but the State Agriculture Department office was able to identify it for me. No one can explain how it got into my garden. I suspect contaminated steer manure. Ugh! A vicious monster!


On Aug 11, 2002, talinum from Kearney, NE (Zone 5a) wrote:

Buffalo Bur is highly invasive in the midwest. The stems are armed with yellow spines, it is very prickly. It reseeds and can take over an area quickly. I am constantly removing this weed.