hawthorn

The cedar quince rust fungus alternates between junipers and rosaceous hosts such as hawthorn, causing stem cankers and fruit infections on the rosaceous host.

  For the last month the fungal tubes of the “aecial” stage of several cedar rust fungi, namely cedar-apple rust (Gymonsporangium juniper-virginianae) and cedar-hawthorn rust (G. globosum) have been evident on leaf undersides of hawthorns, as seen in the accompanying picture.

  These rust fungi spend about a year and half on certain junipers (in the Cupressaceae family) before microscopic spores of the fungus oozing from galls on the juniper blow in the spring to certain genera in the Rosaceae family such as hawthorns and apples and crabapples.

 

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