Daylily Rust Information Pages



Complete Life Cycle Animation


Animation of complete life cycle


  • Later in the year dark brown to black areas develop around and among orange "summer spore" masses on daylily leaves
  • "Winter spores" are produced in darkening areas and remain on dead daylily leaves over winter
  • The following spring these "winter spores" germinate and produce another type of spore that cannot infect daylilies
  • Instead, the new spores infect the "alternate host", Patrinia
  • Once Patrinia is infected, cross-fertilization of the fungus can take place
  • Fertilization results in spores which can infect daylily but not Patrinia
  • Daylily becomes infected by spores formed on Patrinia and the summer asexual cycle resumes (see animation of asexual cycle)


In climates which are sufficiently mild, the asexual cycle can continue through the winter on daylilies and the sexual stage on Patrinia is not required for survival of the disease from year to year as it would be in colder winter climates.  Completion of the sexual cycle results in genetic recombination, increasing the likelihood that daylily rust will overcome rust resistance in some daylily cultivars, however new pathotypes have already been reported in the United States (Buck, J. W., 2013, Identification of Pathotypes in the Daylily Rust Pathogen Puccinia hemerocallidis. Journal of Phytopathology).




2003-2014 text and animation by Susan Bergeron