- Glossary of Botanical Terms
- The Biota of North America Program
- Botany and gardening databases
- Center for Plant Conservation
- Colorado BLM, Botany Program
- Colorado Native Plant Society
- Colorado Plants Database
- Colorado State University Herbarium
- Colorado Wildlife Action Plan, Appendix A: Rare Plants
- Denver Botanic Gardens
- Flora of North America
- Montana Field Guide
- Native Plant Directory
- NatureServe Explorer
- New Mexico Rare Plants
- Southwest Environmental Information Network (SEINet)
- University of Colorado Herbarium
- University of Northern Colorado Herbarium
- USDA PLANTS Database
- US Forest Service: Species Conservation Program
- US Fish and Wildlife Service: Environmental Conservation Online System
- WILDFLOWERS, FERNS, & TREES of Colorado, New Mexico, Arizona, & Utah
