Invasion history of Melaleuca quinquenervia (Cav.) S.T.!Blake in Florida

The Australian punk tree Melaleuca quinquenervia is a notorious invasive weed that threatens the biological integrity of Florida's Everglades ecosystems. A comprehensive plan initiated to manage M. quinquenervia includes an ambitious biological control program, and as part of this program we investigated the origins and invasion history of M. quinquenervia in Florida. Scrutiny of public and private records showed that extant populations derive from more than a dozen introductions, with the earliest occurring during 1886 in Sarasota County. Six sources, some Australian and some extra-Australian, have contributed to Florida's populations. The tree became naturalized in southern Florida during the 1920s, but a paucity of records makes it difficult to determine when naturalized populations began to proliferate via an exponential growth phase. Human distribution of seeds and seedlings is a confounding factor in attempting to decipher rates of M. quinquenervia invasion.