Herbaria Directory
Index Herbariorum
hosted by the New York Botanical Garden, is a detailed directory of the 3000+ public herbaria of the world including staff members associated with it. The electronic searchable version includes up-to-date information on 2010 herbaria in 134 countries.
 

Databases
Gymnosperm Database:
Edited by Christopher J. Earle.  This database has descriptions of 1000+ taxa of gymnosperms, i.e., conifers, cycads, and their allies. This database provides entry at the family level and guides to genus, species and sometimes variety for each taxon. Basic information on each species generally includes a picture, a distribution map, common names, taxonomic notes, description, range, "big tree", oldest, dendrochronology, ethnobotany, remarks, and citations.

Flora of North America
Production of the database proceeds simultaneously with the preparation of the hard-copy flora. The database will eventually contain all the information found in the published volumes as well as additional information, such as more detailed morphological data, information on type specimens, and documentation for chromosome counts.  It will also incorporate information on habitats, precise distributions, populations, and plant communities.

NatureServe
NatureServe is a source for authoritative conservation information on more than 50,000 plants, animals, and ecological communities of the United States and Canada. NatureServe provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe is a product of the Association for Biodiversity Information in collaboration with the Natural Heritage Network.

USDA
The PLANTS Database is a single source of standardized information about plants. This database focuses on vascular plants, mosses, liverworts, hornworts, and lichens of the U.S. and its territories. The PLANTS Database includes names, checklists, automated tools, identification information, species abstracts, distributional data, crop information, plant symbols, plant growth data, plant materials information, plant links, references, and other plant information.
 

Tree Identification
Dichotomous Tree Guide
Developed by the College of Forestry, Oregon State University. Includes pages on What is a genus, a dichotomous key taken from an OSU extension service publication, a list of 15 common trees of the NW with a short description and small picture. This is linked to a species page with four pictures (foliage, size of leaf, bark, and distribution map. The last feature is a mystery tree identification to encourage folks to use the key for genus description, a nice feature.

Using Anatomy and Habitat to Identify a Tree
By Steve Nix for About.com:Forestry. Easy guidelines to tree identification including a link to the 100 Most Common Trees in the U.S. plus parts of the tree; illustrations of common tree leaves, twigs and fruit; tree range and habitat; fall color; and more.

Common Trees of Iowa
Created by the Iowa State University Extension.  Includes a tree identification key, an index of Iowa trees linked to a page with small pictures and description, a definition of a few leaf and fruit terms with diagrams, descriptions of how a tree grows (roots, trunk, crown, and tree form), and a paper on the history of Iowa's trees.

Common Trees of Pennsylvania
Created by the Department of Conservation and Natural Resources. This selection of 57 native, and 5 introduced trees is organized according to leaf shape and arrangement. Each tree is identified by popular name familiar to Pennsylvanians and its complete scientific name.

Common Trees in Eastern and Central US
The National Arbor Day Foundation, c1998. Found on the TreeLink site, a site intended for "people working in urban and community forestry." A simplified identification tree with diagrammatic illustration. Linked to a glossary and index.

Common Trees of Eastern US
Created by the Department of Forestry at NCSU.  The natve pines page is an on-line database designed to assist students studying eastern pines. Emphasis is placed on woody species native or naturalized in eastern North America

Vascular Plants of Texas
This informatics system was developed with support from the Texas Higher Education Coordinating Board.  It has a list of Vascular plant families and species.

Virginia Tech Dendrology
 The Dendrology homepage at Virginia Tech is where to find tree identification
fact sheets on over 450 species of trees, as well as other class information

Winters Trees and Shrubs
Created by Christine Kirk as a Botany class project. Spring 1996. Fifty-four dichotomous characteristics to identify shrubs and trees common to the Brazos Valley (TX).
 

Education Material
Basics of Tree ID
Identification of a tree by following any of six possible paths: tree type, leaves. bark, fruit, twigs, and form or the overall growth pattern of the tree. Each topic is simply described and illustrated with large and beautiful examples. Very nice site for elementary school students

Adopt a Tree
A great way to allow children the opportunity to learn about plants such as trees is to have them actually adopt a tree or group of trees and keep a "tree log" or diary with information about their adopted tree or trees.  This site gives details on how to do this.

Tree Identification
Identification of a tree by following any of the following paths: tree shape, leaf class, fruit type, flower type, bark type.  Each topic is illustrated with large examples.

Earth Awareness Environmental Resources
This is a resource for teachers and students to find useful information in the subject areas of: social studies, geography, science, history, K-12 outreach programs, and the environment. This resource is updated on a weekly basis.

Environmental Education on the Internet http://nceet.snre.umich.edu/ee-linkintroduction.html
The North America Association for Environmental Education created a classroom resource directory.  Teachers can search for desirable activities through the database.
 

Lesson Plans
Biology lesson Plans
The Smile Program Biology Index has a collection of over 200 single concept plans.  These lessons may be freely copied and used in a classroom but they remain the copyright property of the author.