Cenchrus longispinus (Sandbur)
| Also known as: | Mat Sandbur, Common Sandbur |
|---|---|
| Genus: | Cenchrus |
| Family: | Poaceae (Grass) |
| Life cycle: | annual |
| Origin: | native |
| Habitat: | sun; dry, open, sandy soil; roadsides, railroads, prairies, waste areas |
| Fruiting season: | summer |
| Plant height: | 8 to 24 inches |
| Wetland Indicator Status: | GP: UPL MW: UPL NCNE: UPL |
| 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/grass/cenchrus-longispinus-sandbur_0723_120701.jpg)
Spike-like clusters 1 to 4 inches long at stem tips and arising from leaf axils in the upper stem. Flowers are enclosed in round, spine-covered burs, with 2 or 3 spikelets (flower clusters) per bur and 1 fertile flower per spikelet. Mostly hidden from view are the glumes (2 bracts at the base of a spikelet) and lemma (2 bracts surrounding a flower). Glumes are unequal in length and shorter than the lemma. Flower styles and stamens poke out from the tip of the bur. Burs are about ¼ inch in diameter (excluding the spines) and densely short-hairy; spines are barbed, 1/8 to nearly ¼ inch long, and often purplish.
Leaves and stems:
![[photo of stem leaves]](/udata/r9ndp23q/grass/cenchrus-longispinus-sandbur_0722_175635.jpg)
Leaves are all alternate, 2 to 7 inches long, about ¼ inch wide, rough on the upper surface, mostly smooth on the lower, flat or folded lengthwise, sometimes slightly rolled up on the edges.
![[photo of ligule and sheaths]](/udata/r9ndp23q/grass/cenchrus-longispinus-sandbur_0722_175550.jpg)
The ligule (membrane where the leaf blade meets the sheath) is fringed with short, white hairs. The sheath is contracted where it meets the leaf, open at the front, sometimes with sparse, long hairs at the tip or along the edge near the top, keeled (ridged) at the back, somewhat flattened, and loosely surrounds the culm (stem). Nodes are hairless and green or red. Culms are hairless, multiple from the base, often branching, mostly covered by the sheaths, and light green but often tinged red towards the base. Culms may be erect to ascending, but typically sprawling and may root at the nodes.
Fruit:
![[photo of fruit]](/udata/r9ndp23q/grass/cenchrus-longispinus-sandbur_0731_173049.jpg)
The burs persist in fruit, the spines becoming very sharp when dried. They dry to a light tan and latch onto anything that passes by. Inside are 1 to 3 seeds.
Notes:
I hate this plant. If there is one within a mile of me it will find me, ruthlessly attack, and I'll be picking the burs out of my clothes and shoelaces for days. It is often found along sandy roadsides and railroad rights-of-way, where disturbance and unwitting victims like myself helps spread its seed. In some references C. longispinus goes by synonym Cenchrus carolinianus.
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More photos
Sandbur plant
Sandbur plant
side view of sheaths
sticks to everything!Photos by K. Chayka taken at Helen Allison SNA, Anoka County, and Long Lake Regional Park, Ramsey County.
Comments
Have you seen this plant in Minnesota, or have any other comments about it?
on: 2018-07-09 21:39:47
I have found this plant growing in a place that once was manicured lawn. It is a prairie restoration project. I have seen it elsewhere too. This guide has been very helpful.
on: 2018-08-13 19:00:14
My yard is full of these plants, is there any way to get rid of them. We can't have pets, or play in the yard because they are taking over. Thanks for any help you can provide.
on: 2019-01-09 11:54:40
I have found that spreading lime is helpful. They seem to like a more acidic soil which lime will help neutralize.
on: 2020-08-22 16:22:12
My 3 year old son just found one seed pod in his foot at the Starbuck City Park. He then found the rest of the plant growing in the rocks by the slide. We pulled the naughty little thing & threw it on the road.
on: 2020-08-22 16:38:05
...threw it on the road where somebody will drive over it, get it stuck in their tire tread, then deposit the seed somewhere else. Subsequently some other poor soul will get the naughty thing stuck on their shoelaces, pluck it out, toss it in the road, and the cycle will start all over. There is no escaping this evil thing!
on: 2021-04-18 14:12:06
Saw this plant at the end of a driveway on a sandy road.
on: 2022-04-12 17:27:48
ran into this at a WMA near garden city these things go through running shoes
on: 2022-09-10 16:42:56
These plants are prolific along the sandy paths at the Rice Creek Dog Park in Shoreview, MN. The species seems to have two forms: one with stickers, and the other without. Both seem to have the same branching and leafing structure and color. I guess the form with stickers is female, and the other male?
on: 2022-09-10 16:56:14
Scott, sandbur does not have separate male and female plants. It might be possible some plants did not produce seed but I think that would be unusual for an annual. More likely the seed has already hitched a ride on someone's socks, or dog fur.
on: 2022-09-17 19:39:15
I have these plants around my property. I am always picking them by the root by hand. I also belive there is a male and female plant. the one that does not bear seeds looks identical and there are many more of them. They come back every year but never bear seeds and I am slowly getting rid of the bur ones.
on: 2022-09-18 08:31:52
C. Williamson, this species does not have separate male and female plants. It is possible some plants are sterile but that would be unusual for an annual, which can only reproduce by seed.
on: 2022-09-18 20:16:19
I wrote earlier about a different type of grass, with a similar color and growth pattern, that grows mixed with or alongside of Sandbur plants in the Rice Creek Dog Park in Shoreview, Minnesota. I see now that it has small seeds, much smaller than the stickers of the Sandbur plant. In other words, it's not a Sandbur plant that has lost its stickers. I guess this kind of information could be useful in Sandbur control.
on: 2022-09-18 20:37:44
The plant I described in my previous comment as similar in color and growth pattern, but without stickers, might be Digitaria ischaemum (Smooth Crabgrass).
on: 2022-09-19 05:45:50
Scott, if it is only now producing flowers or fruits, it is probably not crabgrass, which would have produced recognizable spikes weeks ago. You can post some images on the Minnesota Wildflowers Facebook page for additional help with an ID.
on: 2023-08-30 18:27:25
Are there any species that can get mixed up with this one? We have burs out at a relative's house on Big Stone Lake, in Yankeetown, Big Stone County, that are very pesky. To note, they also grow on sandy beaches or near beaches there with forbs and various grasses. The prairie at the house/farm is somewhat untouched, and has stayed that way since the late 1800s or early 1900s when the property was first bought and built on.
on: 2023-08-30 19:42:37
Aeron, sandbur is pretty unique and I don't think there is anything else quite like it in Minnesota. It thrives in sandy soil.
on: 2023-09-02 17:53:20
I recently visited my relative's house at Yankeetown in Big Stone County and discovered hundreds of these on the beach there. There are two beaches on the property, and I only visited one, although the other may have many too. It started with only a few plants but has now turned into a whole invasion. I am planning on contacting the Minnesota DNR or botanists about the population on the property before they reach other beaches and sandy sites, which may have already happened.
on: 2023-09-02 18:13:42
Aeron, it is unlikely the DNR or any botanists would be interested in dealing with sandbur on a sandy beach. It's a native plant and, while extremely annoying to humans, it doesn't pose any ecological threat that I'm aware of. If your relative wants it gone, they are free to remove it from their own property as they see fit.