A list of my most-frequently-used online tree references
Taxonomy for higher-level groups (Classes, Orders and Families) in the guide follows the latest revision of the Angiosperm Phylogeny Group. For a quick reference, Wikipedia seems to be an excellent source for good, readable, and up-to-date overviews of taxonomy for most North American plant groups. The North American Digital Flora database lists traditional family placement for each species along with newer “Molecular” family taxonomy.
Species and genus level taxonomy in the guide comes from various sources, among them the PLANTS National Database, the Flora of North America (limited families covered), and the North American Digital Flora created by BONAP.
American Forests National Register of Big Trees
Original native distribution of North American trees is shown in maps in the US Forest Service Silvics Manual
A project to map the trees of Canada with climate variables is interesting to browse at the Canadian Forest Service Plant Hardiness site.
More detailed maps for smaller regions can be found at regional atlas projects such as:
General info and photos
- US Forest Service Silvics Manual
- PLANTS National Database
- Virginia Tech fact sheets of all North American trees
- USFS fact sheets about 680 cultivated trees
- A large collection of tree photos at Forestry Images
- Will Cook’s Trees of North Carolina
- New Brunswick Tree photos
- Flora of North Central Texas
- Photos of California plants at CalPhotos
- Flora of Newfoundland
- Alan Weakley’s “Flora of the Carolinas”
- Project Budburst – click on a species then click to view the pdf “Phenology Guide” showing photos of major events such as flowering and leaf color change.