Update from the Field: Tracking an Invasive Species

Catclaw mimosa (Mimosa pigra)

Catclaw mimosa (Mimosa pigra) is an invasive exotic plant from Central America which was introduced into Florida as an ornamental plant in the 1920’s.  It currently grows in isolated areas of Highlands, Martin, Palm Beach, Broward, St. Lucie and Okeechobee Counties.  It is a thorny sprawling shrub which can form thickets if unchecked.   It has invaded hundreds of square miles in Australia and Southeast Asia making invaded lands almost unusable.  Like the native species of mimosa, sometimes referred to as “sensitive plant,” the leaflets fold up when they are touched.  Catclaw mimosa can invade many habitats from dry uplands to the deepest swamps but prefers moist to wet places.  It is a Category I plant on the Florida Exotic Pest Plant Council’s list of invasive species in Florida and on the US Federal Noxious Weed List and considered one of the 100 World’s Worst Invasive Alien Species by the Global Invasive Species Database.  The Florida Fish and Wildlife Conservation Commission Invasive Plant Management Section (FWC-IPMS) and its predecessors have diligently spent the past 36 years treating it to ensure it does not become a widespread problem in Florida.  

In March 2015, FNAI scientists were asked by FWC-IPMS to survey more than 7,400 acres of conservation lands in Palm Beach and Martin Counties for this species to guide contractors’ upcoming treatment efforts. During this process, FNAI staff walked approximately 600 miles (almost a million meters!) through a variety of uplands, herbaceous marshes and forested swamps.  The good news is that Mimosa pigra does not appear to have expanded its range too much!

Map of transects walked by FNAI biologists on surveys in the Loxahatchee Slough region of southeast Florida.