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Photo Credit: Franz Xaver

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Photo Credit: Forest Starr

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QUICK FACTS

  • HPRWA SCORE 26
  • FAMILY Poaceae
  • CATEGORY Shrubs, Vines, & Others

pampas grass (Cortaderia jubata, Cortaderia selloana)

Considered very invasive; C. jubata is on the Hawai'i State Noxious Weed List. The Division of Forestry and Wildlife of the Hawai'i Department of Land and Natural Resources has designated this species as one of Hawai'i's Most Invasive Horticultural Plants.

  • Large clumping grass that may reach 6 ft or taller
  • Leaves are narrow and have sharp, serrated edges
  • Showy white to purple flower plumes (24 - 31 in) tower three times higher than the foliage
  • C. jubata plants have both female and male flowers and are able to produce viable seeds without cross-pollination
  • C. selloana plants have either male or female flowers and require cross-pollination between male and female plants to produce viable seeds
  • C. jubata was controlled on Mau'i, C. selloana is on O'ahu and Big Island; both species are native to South America
  • Multiple seeds spread far by the wind

Harm

  • In native forests they outcompete native plants, create a fire hazard, and may impact watersheds by changing the natural water cycle.
  • The invasive nature of C. selloana was not historically recognized in Hawai'i because only female plants had been cultivated by cuttings. Male plants are now present and this species is starting to spread.
  • Both are serious pests in California and New Zealand

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