Flora og plantegeografi, trænøgler

Baumkunde.de (Træbestemmelsesnøgle)

Den virtuella floran

eFloras.org

Gymnospermae

The Gymnosperm Database

What Tree is This?

Angiosperm Phylogeny Website

Europa

Deutsches Baumarchiv

Rare and threatened trees and shrubs of Luxembourg

Schweizer Flora

Dutch Treeguide

Plants of Belarus

Laurel Forest of Madeira

Nord- og Sydamerika

Calphotos (Californiens flora i billeder)

Image Archive of Central Texas Plants

Southwest Colorado Wildflowers

UConn Plant Database Main

Native woody flora of Maryland

Maple Tree Identification II

Ontario's ancient and old growth forests

Nøgle til træslægter i CostaRicansk tropisk tørskov (pdf)

The Amazon Plants

Key to trees of Wisconsin

Washington Native Plant Society

Afrika-Asien-Australien

PlantZAfrica.com (Sydafrikanske planter)

Catalogue of the Vascular plants of Madagascar

Guide to Australian plants

Australian Tropical Rain Forest Plants