Arisaema and rust

[Addison & Richardson]

As we walked through various woods earlier this year, we noticed that some
of the Arisaema triphyllum in wild stands seemed to have rust?  Have other
people seen this?  I read the brief bit in Pascal Pirone's Diseases & Pests
of Ornamental Plants....but was wondering if there is more information about
what causes it and how to keep plants clear of it.

Lois Addison
Dunrobin, Ontario       Cdn Z5, US Z4
bedrock.gardeners at sympatico.ca