Our latest count shows 86 native tree species in New Hampshire. The exact number is hard to determine because some are rare, some are mostly found as shrubs, and others can be distinguished from each other only by the most determined dendrologist. This List of New Hampshire Native Trees lists species that are native to at least part of New Hampshire and capable of growing into a tree.
In Native Shrubs, Subshrubs & Lianas of New Hampshire we list 235 species of native shrubs, subshrubs, and lianas in New Hampshire. The exact number is tricky to pin down because some shrubs also occur in tree form and others are subshrubs (dwarf shrubs or perennial plants that are woody only near the base, where new growth above the base dies back each year).
Helpful Characteristics for Identifying Shrubs (and a few trees) in Winter lists key identification points for over 40 shrubs (and some trees). It includes colored pictures of twigs and buds.
Distinguishing Characteristics of 56 Forest Trees is summary of characteristics common forest trees.
Know Your Trees from Cornell describes 50 trees.
Michigan State University has a versatile site with 4 keys moving you through to identification. Easy to use and fully illustrated.
"Go Botany" provides this useful site
Forest Biology and Dendrology at Virginia Tech includes tree identification fact sheets for 450 species. Figure out your unknown specimen, using the twig or leaf key. Easy to use and fully illustrated.
The National Plants Database is a single source of standardized information about plants. It covers vascular plants (such as trees), mosses, liverworts, hornworts, and lichens of the US and 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.
A Partial Listing of Publications on Tree and Shrub Identification should help serious students find additional books to add to their library.
Here is a series of short videos for over 130 trees and counting! They are produced by the State University of NY, College of Environmental Science and Forestry