Over here, 'preserves' is regarded as a slightly pretentious synonym for jam. One would expect to find seeds in, e.g., good raspberry jam. We just wouldn't say 'raspberry preserve' unless we were Hyacinth Bucket (a much satirised social climbing character in one of our popular tv sitcoms, who, e.g. insists on pronouncing her surname as if spelt 'Bouquet').

There appears to be no doubt that in this area the British and Americans are indeed divided by that common language. The best we can hope for, it seems to me, is to learn one another's usages and hope to get them right when visiting or contacting the others' country.