Xanthium strumarium


Erect annual. Stems thick and fleshy, spineless, green spotted red or black. Leaves alternate, 6 in. long, triangular with long petiole, a few glands on surface, coarsely toothed or lobed. Flowers very small, insignificant. Seeds held in tight clusters of round to oblong burrs at axils of leaf stalks and stems. Found in disturbed soils throughout the world. In Pacific Northwest found at low elevations. Xanthium is Greek for "yellow," the color of dye extracted from the fleshy stems.

  • Rarity: Uncommon
  • Flowering Time: Late Summer-Autumn
  • Life Cycle: Annual
  • Height: 12--60 inches
  • Habitat: Vernal Wet, Disturbed
  • Found In: West Gorge, East Gorge
  • Native: Yes