Most City offices closed Wednesday, June 19, to observe Juneteenth

The City of Portland recognizes Juneteenth as a formal day of remembrance to honor Black American history and the end of slavery in the United States. Learn about Juneteenth.

More Tree Species References

Find references about tree species.

Online Database References

Tree Identification

Plant Database (University of Connecticut College of Agriculture, Health and Natural Resources)

Virginia Tech Dendrology Factsheets (Department of Forest Resources and Environmental Conservation)

General Information on Individual Species

The Gymnosperm Database (Edited by Christopher J. Earle)

SelecTree (Urban Forests Ecosystem Institute at California Polytechnic Institute)


Global Invasive Species Database

Tallest and Oldest Trees

Monumental Trees website (The thickest, tallest and oldest trees worldwide)

Print References

General References

  • The Book of Leaves by Allen J. Coombes edited by Zsolt Debreczy (The University of Chicago Press, 2003)
  • Manual of Woody Landscape Plants by Michael A. Dirr (Stipes Publishing,1998)
  • New Trees:  Recent Introductions to Cultivation by John Grimshaw and Ross Bayton (Kew Publishing, 2009) 
  • North American Landscape Trees by Arthur Lee Jacobson (Ten Speed Press, 1996)
  • Northwest Trees by Stephen F. Arno and Ramona P. Hammerly (The Mountaineers Books – revised edition, 2007)
  • Silvics of North America by Russell M. Burns and Barabara Honkala (USDA Forest Service, 1990)
  • The Tree Book by Michael A. Dirr & Keith S. Warren (Timber Press, 2019)
  • Trees for All Seasons by Sean Hogan (Timber Press, 2008)
  • Trees of Seattle (second edition) by Arthur Lee Jacobson (2006)
  • Trees of the California Landscape by Charles R. Hatch (University of California Press, 2007)
  • Uncommon Fruits for Every Garden by Lee Reich (Timber Press, 2004)
  • The World Encyclopedia of Trees by Tony Russell, Catherine Cutler, and Martin Walters (Armadillo, 2014)

Genus-Specific References

  • An Illustrated Guide to Maples by Antoine le Hardy de Beaulieu (Timber Press, 2003)
  • Magnolias: A Gardener’s Guide by Jim Gardiner (Timber Press Revised Edition, 1989)
  • Oaks of California by Bruce Pavlik, Pamela Muick, Sharon G. Johnson, Marjorie Popper (Cachuma Press, 2002)


  • A Natural History of Conifers by Aljos Farjon (Timber Press, 2008)
  • Conifers of California by Ronald M. Lanner (Cachuma Press, 1999)
  • Conifers of the World: The Complete Reference by James E. Eckenwalder (Timber Press, 2009)