CalFlora Database - provides access to information about all 8375 currently recognized plants in California, including more than 670,000 plant observations and 20,000 photographs.
Internet Directory for Botany - an index to botanical information available on the Internet. It consists of two parts, an alphabetical directory and a categorical directory.
MBG: W3TROPICOS - Database of plant names, information on them, and the sources of information.
Plants For a Future - A resource centre for rare and unusual plants, particularly those which have edible, medicinal or other uses. The site contains an online database of over 7000 plants.
USDA PLANTS Database - Plant names, photos, fact sheets, and information on culturally significant plants, noxious and invasive plants, and threatened and endangered plants, with links to thousands of plant-related sites and software tools.
