Science.gov
Provides access to authoritative, selected science information from U.S. Government agencies, including research and development results.
Tree of Life
Organisms and their evolutionary history and taxonomy.
Department of Agriculture (USDA)
Public policy on food, agriculture, natural resources, rural development, nutrition, and related issues.
Biodiversity Heritage Library
A consortium of natural history and botanical libraries that cooperate to digitize the legacy literature of biodiversity held in their collections.
Google Patents
Full text US patent documents from 1790 to the present that is fully indexed and searchable.