The Animal Diversity Web is an online database and encyclopedia of animal natural history, built through contributions from students, photographers, and many others.
The Biodiversity Heritage Library improves research methodology by collaboratively making biodiversity literature openly available to the world as part of a global biodiversity community.
iNaturalist helps you identify the plants and animals around you while generating data for science and conservation.
The Tree of Life shows how all life on Earth is related. Each leaf represents a different species, and the branches illustrate how these many species evolved from common ancestors over billions of years.
OpenTrees.org is the world's largest database of municipal street and park trees, produced by harvesting open data from dozens of different sources.
Free silhouette images of animals, plants, and other life forms, available for reuse under Creative Commons licenses.
The aim of a World Register of Marine Species (WoRMS) is to provide an authoritative and comprehensive list of names of marine organisms, including information on synonymy.