Last modified 13th February, 2025

• Arizona Sonora Desert Museum
• Australian Succulents
• The Bolus Herbarium
• Cactus Conservation Institute Inc
• Cactus Explorers Club
• Cacti of Nicaragua
• The Chihuahuan Desert Research Institute
• ELK
• The Epiphytic Plant Research and Information Centre
• International Organization for Succulent Plant Study/li>
• Institute for Aloe Studies
• Kaktus Rehberi Pages in Turkish compiled by members of the Turkish Cactus Association.
• Living Desert Wildlife and Botanical Gardens
• The National Botanical Institute (South Africa)
• The Peyote Foundation