American Society of Plant Biologists (ASPB) - To promote the growth and development of plant biology, to encourage and publish research in plant biology, and to promote the interests and growth of plant scientists in general
Botanical Society of America - Promoting research and teaching in all fields of plant biology to facilitate cooperation among plant scientists worldwide and to disseminate knowledge of plants, algae and fungi. Links to the American Journal of Botany, Plant Science Bulletin, national meetings and symposia, and educational resources.
Botanical Society of the British Isles - Founded in 1836, it is the major source of information on the status and distribution of British and Irish flowering plants and ferns.
California Botanical Society - Systematics, ecology, evolution, and natural history of the plants of California and adjacent western North America. Publisher of the journal MadroƱo.
Philadelphia Botanical Club - Society presents its long history, meetings and field trips, herbarium, journal, and officers, with a membership form.
World Botanical Associates - Organization formed to collect plants for pharmaceutical screening and research. Maintains a herbarium and issues taxonomic reports.