Skip to content.
Français

Some features of this website require Javascript to be enabled for best usibility. Please enable Javascript to run.

Ministry of Agriculture, Food and Rural Affairs

Long-spined sandbur

Scientific Name: Cenchrus longispinus (Hack.) Fern.

Other Names: cenchrus épineux, Bur grass

Family: Grass Family (Graminae)

General Description: Annual, reproducing only by seed.

Habitat: Long-spined sandbur is a native grass in areas of sandy soil throughout southern Ontario. Though normally found along sandy beaches, sand dunes, riverbanks and roadsides, it is becoming a problem in tobacco fields, other row crops and occasionally in lawns and gardens on sandy soils.

Stems

  • 10 - 60 cm (4 - 24 in.) long,
  • Erect or spreading or lying on the ground,

Leaves

  • Flat or margins enrolled,
  • Usually constricted and partially twisted at the junction with the leaf sheaths,
  • 2 - 12 cm (1 - 5 in.) long,
  • Mostly hairless but rough in one direction,
  • Sheaths:
    • Split with overlapping margins,
    • These margins on young plants membranous and without hair, but on upper leaf sheaths of older stems and membranous and usually with few to many hairs 1 - 2 mm (1/25 - 1/12 in.) long.
  • Ligule a fringe of hair mostly less than 1 mm (1/25 in.) long,
  • There is a tuft of short and long (2 - 3 mm, 1/12 - 1/8 in.) hair on each side of the collar at the junction between blade and sheath,
  • No auricles.

Flowers

  • Inflorescence a group of spiny burs at the end of each stem,
  • Each bur 4 - 6 mm (1/6-¼ in.) long, containing 1 or 2 “seeds”, and covered with extremely sharp spines 2-6 mm (1/12 - ¼ in.) long with backward-pointing barbs which anchor into skin, etc., the whole bur breaking off when mature.
  • Flowers from August to September.

Often Confused With
Foxtail seedlings – By digging up a seedling, a prominent bur should be attached to the base of the root, the soil surface may have burs.

Younger plants can be distinguished from most other grasses by the split sheath with membranous margins, and usually some hair on the margin, together with the hairy ligule and the tufts of long hair on either side at the junction between blade and sheath. Once the burs have emerged, long-spined sandbur cannot be confused with any other grass in Ontario.

Long-spined sandbur Long-spined sandbur. A. Plant. B. Leaf-base. C. Bur enclosing spikelet. Long-spined sandbur Long-spined sandbur
Click to enlarge.