Introduction to the Green Kingdom
Brief introduction to the plant kingdom with links to further information.

Names in Current Use for Extant Plant Genera
International Association for Plant Taxonomy searchable database.

Natural Perspective: Plant Kingdom
Introduction to the Plant Kingdom with information on some of the divisions which make up this group.

CalFlora Database
Searchable database all 8375 currently recognized vascular plants in California, including 20000 photographs.

The Oldest Land Plants
Introduction to the first land plants, known from fossils.

FloraBase - The Flora of Western Australia
Authoritative scientific information on 12,000 taxa in Western Australia, including maps, images, descriptions, specimen, and nomenclatural information. Requires registration.

International Plant Names Index
Database of the names and associated basic bibliographical details of all seed plants.

Botanical Word Meanings and Name Derivations
References on California plant names, meanings and derivations from Latin and Greek roots, with biographical information on western botanists and collectors.

Land Plants Online
Southern Illinois University's guide to the taxonomic and evolutionary relations among terrestrial plants, with extensive links to other resources.

Forestry Images - Plants
Small collection of plant imagery, from University of Georgia.

PLANTS National Database
Online USDA database of information, images, and links on plants in the USA, including crops and invasives. Search by name, geographic distribution, or other characteristics.

Index Nominum Genericorum
A collaborative project of the International Association for Plant Taxonomy and the Smithsonian Institution, providing a compilation of generic names published for all organisms covered by the International Code of Botanical Nomenclature.

Dictionary of Botanical Epithets
Glossary of Latin terms used in species names, from abbreviatulus to yunnanensis.

Synonymized Checklist of the Vascular Flora of the United States
Full text index of the 1998 version of the Biota of North America Program's checklist.

Kingdom: Plantae
A growing directory of the hierarchy, from Kingdom down to species, with common names included, and descriptive pages on selected species.

Atlas of the Flora of New England
Continuing project with annotated checklists of pteridophytes, gymnosperms, and most monocots, with links to dot maps for each taxon.

Flora of Hokkaido
Distribution maps of vascular plants of Hokkaido, Japan.

Illustrated Flora of North Central Texas
Information including keys, descriptions and illustrations of species available in Adobe pdf format by Shinners and Mahler.

Hawaiian Native Plant Genera
Images of hundreds of species of ferns, fern allies, and flowering plants, arranged by genus.

Digital Flora of Texas - Vascular Plant Image Library
Large collection of photographs, arranged by family.

Albion College Vascular Plant Image Gallery
Taxonomically arranged images and summaries of family characteristics.

National Herbarium Nederland
Information about the research themes and training undertaken at the national herbarium of the Netherlands, with links to the three contributary universities.

University of Florida Herbarium (FLAS)
The herbarium and the associated paleobotanical collection have combined holdings of approximately 1/2 million specimens. Includes library search, catalog, and project information.

University of Manchester: British Flowering Plants
Searchable, illustrated collection.

Glossary of Roots of Botanical Names
Meanings of over 1000 root words used in scientific names of plants.

Caudiciforms
Information and photos of many species of caudiciforms - plants with thickened bases.

Kew Record of Taxonomic Literature
Database of references to publications on the taxonomy of flowering plants, gymnosperms, and ferns.

National Plant Data Center
Responsible for the PLANTS database, which focuses on the vascular and non-vascular plants of the United States and its territories, including checklists, species abstracts, distribution data, crop information, plants symbols and plant growth data.