Wildflowers JAPANESE KNOTWEED: (Fallopia japonica or Polygonum cuspidatum). Although the flowers of this large herbaceous perennial plant may be said to be somewhat attractive, this plant is placed among the worst Plant blindness: Have you hugged a wildflower today? Florida Wildflower Foundation Top Ten Largest Hydro Plants in the United States Certrec How to care for philodendron asplundii to prevent corkscrew growth Oxford University Plants 400: Indigofera tinctoria