Mat Sandbur is a loosely clumped summer annual grass with branching stems, referred to as culms, of up to 2.5' long. Under certain conditions, it can persist as a biennial or perennial. It is also considered a winter annual, that is, it can live for one year, with a winter included. Several culms are produced from the base that may sprawl along the ground or stand in an ascending fashion. In their natural habitat, they can be found growing in sandy sites, abandoned fields and in areas that have been disturbed recently. Its aggressive, invasive nature is intensified by its bur's ability to latch onto the fur of animals and the clothing of passersby to be spread to other locations. They can also attach themselves to vehicle tires or be washed to new locations via rainfall. Additional rooting can take place where the nodes touch the ground. The main flower stalk axis is wavy. Typically, each spike can contain 40 and occasionally up to 50 burs. The spike is enclosed by a leaf sheath. They often form large mats and can grow up to 2' in length. Insects, Diseases, and Other Plant Problems: This plant can be invasive. The burs can prick the skin when dry out. Farm animals are often injured when grazing in locations where this plant is growing, often injuring their mouths and eye.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Sand
Soil drainage
Good Drainage | Occasionally Dry
Available space
12 inches-3 feet
NC region
Coastal; Mountains; Piedmont
Growth rate
Medium
Maintenance
High
Form & Appearance
Habit / form
Ascending; Horizontal; Prostrate; Spreading
Texture
Coarse
Leaf color
Green
Leaf type
Sheath
Leaf arrangement
Alternate
Leaf shape
Linear
Leaf feel
Rough; Smooth
Leaf size
3-6 inches long, < 1 inch wide
Hairs present
No
Leaf detail
The leaves, that can reach lengths of up to 6", form along the entire length of the stems. The upper side is rough, with a smooth lower surface. They can be flat, or folded lengthwise and sometimes rolled up slightly on the edges.
Flower color
Brown/Copper; Green; Purple/Lavender
Flower form
Panicle; Raceme
Flower shape
Irregular
Flower size
< 1 inch
Flower detail
The flower is a spike-like clusters of 1-4" long at the stem tips. They are enclosed in round, spine-covered, yellow-green burs.
Bloom time
Fall; Summer
Fruit color
Cream/Tan
Fruit type
Caryopsis
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
The fruits are contained in the spiny burs that are along the terminal panicle. They consist of 1 to 3 seeds each. When dried, the burs become sharp and attach to the clothing or shoelaces of passersby.
Stem color
Green
Stem detail
The light green stems or culms is covered by a sheath of leaves. They may have a reddish color near the base.
Wildlife & Ecology
Native status
Native
Origin
North America, Mexico and South America
Distribution
AL, AR, AZ, CA, CO, CT, DC, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME MI, MN, MO, MS, MT, NC, ND, NE. NH, NJ, MN, MV, NY, OH, OK, OR, PA, RI, SC, SD, TN, TX UT, VA, TV WA, WI, WV, WY
Food & Medicine
Harvest time
Summer
Fruit type
Caryopsis
Landscape Use
Garden tags
#summer annual #warm season weed #warm-season grass #aggressive #burrs #problem for cattle #problem for horses #high maintenance #annual #weedy grass #weedy