- Worldwide distribution. On Canna and relatives.
- Yellow to tan powdery spots on leaves and stems, often parallel to veins, becoming dark. Leaves die early. Spores ('urediniospores') spread in wind, but need water to germinate.
- A disease affecting the quality of ornamentals.
- Cultural control: remove infected leaves when spots first appear; do not compost the diseased leaves.
- Chemical control: copper or mancozeb.