An article by Pat Breen, Oregon State Univ., Dept. of Horticulture describing common characteristics of plants that are useful in identifying them.
Keyword: Plant identification
Interactive Keys – Descriptions, Illustrations, Interactive Identification, and Information Retrieval from DELTA Databases
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.
Flora of North America
FNA’s mission statement reads: “FLORA of North America (FNA) is a project undertaken by North American botanists to provide authoritative, up-to-date information on the names, relationships, characteristics, and distributions of the approximately 21,000 species of plants that grow outside of cultivation in North America north of Mexico.” This extensive database of North American plants is organized by family, then down the line by genus and species. The information provided includes a detailed botanical description, citations to selected references, line-drawing images, which can be enlarged to positively identify the plant, and relevant links.
King County Noxious Weed ID
Photos and descriptions for weed identification in King County, WA. Search by common name, Latin name, or thumbnail photo.
Desert USA: Desert Plants
An informative site with photos and cultural information on a number of desert flowers, trees, and shrubs. It also includes links to related articles about desert wildflowers and life in the desert.
Bioimages
A large collection of plant images, mostly woody trees and shrubs, with various browsing methods to find the images. The most useful method is a map of North America divided into bioregions. Each bioregion has an associated list of dominant plants. Created by Steve Baskauf of Vanderbilt University.
UC Davis IPM Online Guide to Healthy Lawns
Identification key to weeds