Saw Greenbrier

Panhandle

Bay, Calhoun, Escambia, Franklin, Gadsden, Gulf, Holmes, Jackson, Jefferson, Leon, Liberty, Okaloosa, Santa Rosa, Wakulla, Walton, Washington

North

Alachua, Baker, Bradford, Clay, Columbia, Dixie, Duval, Flagler, Gilchrist, Hamilton, Lafayette, Levy, Madison, Marion, Nassau, Putnam, St. Johns, Suwannee, Taylor, Union

Central

Brevard, Citrus, DeSoto, Hardee, Hernando, Highlands, Hillsborough, Indian River, Lake, Manatee, Okeechobee, Orange, Osceola, Pasco, Pinellas, Polk, St. Lucie, Sarasota, Seminole, Sumter, Volusia

South

Broward, Charlotte, Collier, Glades, Hendry, Lee, Martin, Miami-Dade, Palm Beach

Keys

Monroe

67 of 67 counties, from research-grade iNaturalist observations. They show where people have photographed it, not every place it grows — absence here isn't proof it's absent.