Instruct: Classify an Amazon review into positive or negative sentiment.
Query: Disappointed

I found the book disappointing in that it ignores the five recognized species of native irises of the southeastern coastal states, some extending up the MississippiRiver valley as far as IL and OH. I. nelsonii may not be a true species and perhaps one or two in FL are entitled to species status. They are all, with their hybrids developed since the 1940's, generally included in the designation "Louisiana Irises", with an international society of several hundred members and are included in honors and awards of the American Iris Society. See the website "SLI". While the book may be the best available, what else is missing? We need something much better.