Berry Botanic Garden: Information on Pacific Northwest native plants, plant collections and native endangered plant conservation.
NatureServe Explorer: Information on more than 65,000 plants, animals, and ecosystems of the United States and Canada, including particularly in-depth coverage for rare and endangered species.
Rare, Threatened and Endangered Species of Oregon List: (ORNHIC, PDF - 1.3MB): Summarizes in list format rare, threatened and endangered plant, animal and invertebrate species, including those that are at-risk or potentially at-risk.