List of plant species (over 28,000 names) that have been cited in specific references as weeds. Additional information may be available, such as native range, whether the plant has reported medical/herbal uses, etc.
Provides information on the classification, structural features, natural history, ecology and evolutionary relationships of bryophytes (mosses, liverworts and hornworts).
Provides biodiversity knowledge about all known species, including their taxonomy, geographic distribution, collections, genetics, evolutionary history, morphology, behavior, ecological relationships, and importance for human well being.
Flora of the vascular plants of the Canadian Arctic Archipelago with images, maps and information on place of valid publication, synonymy, common names, vegetative and floral morphological characters, distribution, habitat, ecology, indigenous knowledge, and economic uses, etc.
The PLANTS Database provides standardized information about the vascular plants, mosses, liverworts, hornworts, and lichens of the U.S. and its territories.