Longspine Sandbur
Cenchrus longispinus
Washington State Classification
Class C — Widespread, County-Selected Control
Longspine sandbur was changed from a Class B to a Class C noxious weed in 2013.
Quick Reference
Identification
Growth Habit
Annual that forms mats, blooming mid summer to late fall. Plants are wind pollinated.
Leaves
Leaves have open (not fused) sheaths. Sheaths compressed and keeled. Hairs present along upper sheath margins and where leaf blade and sheath meet (ligules). Leaf blades can be flat or folded, generally up to 8.5 inches long by 0.12 to 0.24 inches wide.
Flowers
Inflorescence can be partially enclosed in sheath, made up of spiny burs, typically with 2 (up to 4) florets each. Numerous spines per bur, sometimes purple tinged. Burs have fine hairs.
Fruit & Seeds
Seed in burs that turn brown as seeds ripen.
Impact
Longspine sandbur was changed from a Class B to a Class C noxious weed in 2013.
Ecology & Spread
Habitat
It grows in open, sandy areas, along riverbanks and disturbed areas. Please click here to see a county level distribution map of longspine sandbur in Washington.
Spread Mechanisms
Reproduction
Burs spread by attaching to animals and people.
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