Features more than two million high-resolution type specimens. Also includes partner-contributed reference works and primary sources, such as collectors’ correspondence and diaries, paintings, drawings, and photographs.

Information on the names, taxonomic relationships, continent-wide distributions, and morphological characteristics of all plants native and naturalized found in North America north of Mexico.

Germplasm Resources Information Network (GRIN) provides the classification and nomenclature: scientific names, common names, geographical distributions, literature references, and economic impact.

Database of the names and associated basic bibliographical details of seed plants, ferns and lycophytes. IPNI is a dynamic resource, depending on direct contributions by all members of the botanical community. (Note: does not have information on accepted names and taxonomic synonyms.)

This web site provides structured access to a teaching collection of plant images representing over 250 families and 1500 genera of vascular plants.

Provides standardized information about the vascular plants, mosses, liverworts, hornworts, and lichens of the U.S. and its territories. It includes names, plant symbols, checklists, distributional data, species abstracts, characteristics, images, crop information, automated tools, onward Web links, and references.

International network and research infrastructure for biodiversity data. Content includes specimens, data sets, and geotagged species occurrence records and information.

Nomenclatural, bibliographic, and specimen data. Nearly 1.3 million scientific names and over 4.4 million specimen records.

Authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world. A partnership of U.S., Canadian, and Mexican agencies (ITIS-North America), other organizations, and taxonomic specialists.