(H. Hansen) Medium Hosta ‘American Sweetheart’ is a tetraploid version of ‘Sea Thunder’ which was named in honor of Mildred Seaver, America’s “Queen of Hostas”. Like its parent, it displays green leaves with a white center. However, the tetraploid version has a much wider green margin and much thicker leaves, which are held more upright than ‘Sea Thunder’. Lavender flowers top the clump in August