About.com: Botany: A page of links and articles.
BioScience Research Tool: Botany: Specialized directory of online tools and resources selected for Botanists, Plant Physiologists, and Plant Molecular Geneticists.
Botanical Authors Database: Search the database of authors who contributed to the contents of the catalog of type specimens in the Harvard University Herbaria.
Botanical Publications Database: Database of publications used to verify the entry of publication names in the Harvard Herbaria catalog.
Botanical Society of America Image Collection: Collection of 14 sets of educational images for instructional use, with search capability.
Botany Encyclopedia: Includes a botanical dictionary, advice for gardeners, and a store selling plants.
Botresearch USA: a botanical research and biotechnology organization specializing in tissue culture, photomicroscopy, and the production of educational materials for universities.
Center for Plant Conservation: Collaborative organization dedicated to conserving and restoring the rare native plants of the United States. Includes information on conservation techniques.
Cladistics or Supercilious?: Textual review of the development of evolutionary trees in botany. Written by Henry Loconte.
Glossary of Botanical Terms: Contains more than 2,500 terms relating to botany, gardening, horticulture and landscape architecture. Fully searchable and it is regularly updated.
Green Plant Phylogeny: Green plant phylogeny research coordination group.
Hunt Institute for Botanical Documentation: A division of Carnegie Mellon University. Archives, research, art, and information about the institute are included.
Institute for Plant Ecology: Information about research and teaching activities with focus on biodiversity and ecophysiology in different climatic regions, based at the University Münster.
International Centre for Research and Training on Seabuckthorn: Information on the biology of this plant and its uses for environmental, economic, nutritional, and medical purposes; emphasizing erosion control.
International Plant Genetic Resources Institute: Contains information on IPGRI, resources, and press releases.
Max Planck Institute for Plant Breeding Research: Conducts research programs on molecular-biological, genetical, biochemical, physiological and cytological aspects of plant development and plant breeding. [English and German versions available.]
Plant Tissue Culture Information Exchange: Intended to give researchers, teachers and producers rapid access to information about plant tissue culture.
Root Biology and Mycorrhiza Research Group: Descriptions of current research projects at the Department of Botany, University of Guelph, Ontario, Canada.