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Integrated Crop Management
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Longspine sandbur

Longspine sandbur                Cenchrus pauciflorus Benth.

Family:  Poaceae (Grass family)

Life cycle:   Annual

Habitat:  Disturbed areas, particularly sandy sites.  Edges of fields.

Native status:

General description:  Prostrate or semi-erect growth habit, reaching heights up to 20 inches.  The plant has a hairy ligule, the collar is narrow and lighter in color than the rest of the sheath, and occasionally has long hairs on margin.  Influoresence is a spike with burs possessing sharp spines (up to ¼”), spike often partially enclosed in leaf sheath.  Each bur contains one to three grains (seed).

Key ID traits:  Leaves are folded, resulting in a flat stem.   Small seedlings will have the bur attached to roots.

Similar species:  Field sandbur.

Miscellaneous:  Spines of burs have microscopic, backward pointed barbs that make removal from skin or clothing difficult.  Doesn’t tolerate shade very well, so is uncommon in crop fields.  However, may occur on field edges.  It is found on many ISU farms due to the presence of alleyways allowing more sun penetration.

spines on burs are barbed, making them difficult and painful to remove
Spines on burs are barbed, making them difficult and painful to remove
inflorescences are often partially enclosed within the leaf sheath
Inflorescences are often partially enclosed within the leaf sheath
Authored by:
Bob Hartzler
Bob Hartzler
  • Retired Weed Scientist and Professor of Agronomy
Dr. Bob Hartzler is a former professor of agronomy and a former extension weed specialist with a Ph.D. in Crop Physiology from Iowa State University. He conducted research on weed biology and how it impacts the efficacy of weed management programs in corn and soybean. Dr. Hartzler also taught undergraduate classes in weed science and weed identification.
Meaghan Anderson
Meaghan Anderson
  • Field Agronomist in Central Iowa
Meaghan Anderson is a field agronomist serving nine counties in central Iowa and an extension specialist with Iowa State University Extension and Outreach. Areas of expertise include weed management, weed biology, cover crops, corn and soybean management, and integrated pest management.

Meaghan holds a bachelor's degree in agronomy and a master's degree in crop production and physiology (focus: weed science) from Iowa State University.

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