Invasive garden plants. Illustration of a gardener cultivating the invasive flowering plants periwinkle (Vinca major, blue) and pampas grass (Cortaderia selloana, right). They have spread outside the garden, damaging the natural ecosystem (seen in the background). Invasive species often lack natural predators, compete with native species, and threaten indigenous wildlife. Invasive species also threaten the biodiversity of the native ecosystem. These plants are invasive in California, USA, where they are a wildfire hazard and lower species diversity. For the ecofriendly alternative, see images C028/6528 and C028/6529.