I thought that ants were necessary for the buds to open, but according
to www.peonies.org, the ants are symbiotic (commensal) to the plant
and neither help nor harm it. The ants get a nice lunch out of the
deal, however.

JD
Canon 1D-mkIII
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e-mail: blissful-wind(at)usa.net

Additional images at;
http://www.flickr.com/photos/john-pa/