Recommended Websites: Plant Identification and Diagnostics

A tour of trees on the University of Washington campus, including a map, descriptions and pictures.

A tree selection guide from Cal Poly Urban Forests Ecosystems Institute including trees native to CA and elsewhere.

Resources for identifying plants, angiosperms, gymnosperms, flowers, fruits, seeds and leaves.

Insect, disease, and other images

An article by the Northeastern Area of the US Forest Service that describes diseases caused by non-living agents, such as winter damage, sun scald and herbicide damage.

This site makes available numerous data sets of plants and animals that work with a free program called IntKey. First download and install this small program, then download a data set such as Grass genera of the world or Flora of China, which will trigger the program to run. By selecting certain traits, such as leaf shape, non-conforming taxa are eliminated.

An article that introduces you to the basic patterns of identification for seven of the largest and easiest-to-recognize families of plants, which are found worldwide.

This site provides assistance with identifying common conifers in the Pacific Northwest. It includes information about specific genera, user-friendly dichotomous keys, and a mystery tree section where you can test your knowledge.

Oregon State University presents their online version of a guide to plant diseases. Search by the common name of either the plant or the disease. Each record describes the cause, symptoms and control for the particular disease, and most have a picture. The site also gives detailed instruction on how to submit a diseased plant sample to the Oregon State University clinics as well as addresses for the many official County Extension clinics in the Pacific Northwest.

An article by Pat Breen, Oregon State Univ., Dept. of Horticulture describing common characteristics of plants that are useful in identifying them.

Help for identifying plants, trees and lichens of Washington. This simple random access key can help you identify an unknown plant by narrowing the number of species that could possibly match your plant.

A pamphlet by the US Forest Service on preventing, identifying and caring for tree wounds.

A classic handbook by Alex Shigo, tree expert and former pathologist for the US Forest Service. The handbook demystifies how and why trees decay and how decay can be slowed or accelerated.

If you have an unknown tree specimen, you can try to figure out what it is by using one Virginia Tech's leaf or twig keys.

Help with identifying trees by leaf, by fruit and by name--click on the chain of illustrated characteristics (fruit, leaf) for the tree you want to identify until you narrow it down to a genus and species with the help of this informative website. It features common trees of Ohio.

The National Arbor Day Foundation's version of a tree identification tool. A series of pictures and questions are used like a dichotomous key to identify mystery trees by process of elimination. A very good animated interactive tutorial illustrates how to use a dichotomous key.

Master Gardeners are volunteers, trained by WSU, to provide research-based information on home gardening and pest control. This page links to the clinic schedule and locations to all 35 clinics in King County. The clinics are free for non-professional gardeners.

A service for professional gardeners and arborists that diagnoses plant and insect samples for a fee.

"The Pest Leaf Series (PLS) was initiated in the WSU Puyallup Plant & Insect Diagnostic Laboratory to produce brief "bulletins" on problems frequently received at the laboratory, for which no formal extension bulletins or other readily available information exists. The PLS covers insect problems, diseases, abiotic problems, and other miscellaneous situations on which we are regularly asked to provide information."