The list below includes links to some of these groups:

The American Public Gardens Association
American Bamboo Society
American Begonia Society
American Horticultural Society
Botanic Gardens Conservation International
Botanical Society of South Africa
The Bromeliad Society International
The Cactus and Succulent Society of America
The California Rare Fruit Growers
Council on Botanical and Horticultural Libraries
The Cycad Society
Cycad Society of South Africa
International Geranium Society
International Waterlily and Water Gardening Society
Los Angeles International Fern Society
The Mediterranean Garden Society
Montgomery Botanical Center
North American Plant Collections Consortium
Orchid Society of Santa Barbara
Pacific Horticulture Foundation
Palm and Cycad Societies of Australia
Palm Society of Southern California
Royal Botanical Garden Kew
Society for Economic Botany
Succulent Society of South Africa