Least Wanted Invasive Plant Species

The Plant Conservation Alliance (PCA) is a consortium of 10 federal government member agencies and over 290 non-federal cooperators representing various disciplines within the conservation field: biologists, botanists, habitat preservationists, soil scientists, etc. PCA members and cooperators work collectively to solve the problems of native plant extinction and native habitat restoration, ensuring the preservation of our ecosystem. PCA embodies the axiom: "Think Globally, Act Locally." Learn more about the Plant Conservation Alliance. 

  1. Black Swallow-Wart
  2. Common Reed
  3. Garlic Mustard
  4. Japanese Knotwood
  5. Perennial Pepperweed

Black Swallow-WartBlack Swallow-Wart

Cynanchum Louiseae Kartesz & Candhi - Milkweed Family

Black or Louis’ Swallow-Wart is a perennial, twinning herbaceous vine. The leaves are oval shaped with pointed tips and occur in pairs along the stem. The small five-petaled star shaped flowers are dark purple to almost black with white hairs. Learn more about Black Swallow-Wart (PDF).