Melanthera nivea (Asteraceae) image 135873 at PhytoImages.siu.edu
Snow squarestem - Florida Wildflower Foundation
Making It Grow - Melanthera nivea no widely used common name sometimes called showy squarestem although flowers aren't particularly prominent. In aster family and in my garden is at least three by
Salt and Pepper - Melanthera nivea (1 gal.) – Little Red Wagon Native Nursery
Melanthera nivea (L.) Small | Plants of the World Online | Kew Science