PlantWorld
- Photographic directory of plants from around the world arranged by family and genus.
- http://www.plantworld.org

Photo Herbarium
- Einar Vaernes has produced a photograph gallery of Norwegian plants that he has photographed near Trondheim.
- http://www.vaernes.net/einar/fotoherbarium/main_e.htm

Flora brasiliensis
- Online version of the series of books produced between 1840 and 1906 by editors Carl Friedrich Philipp von Martius, August Wilhelm Eichler and Ignatz Urban with the participation of 65 specialists. [English and Portuguese versions].
- http://florabrasiliensis.cria.org.br/

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.
- http://ravenel.si.edu/botany/ing/

Plants For A Future
- Information about a wide range of edible or otherwise useful plants, sorted by names and potential uses. Includes a searchable database.
- http://www.pfaf.org/

Kingdom: Plantae
- A growing directory of the hierarchy from Kingdom down to species. Includes descriptive pages on selected species.
- http://www.kingdomplantae.net/

Discover Life - Plantae
- Checklists, images, maps, and identification guides.
- http://www.discoverlife.org/nh/tx/Plantae/

Flora of Europe
- Photographic herbarium organized by plant family and genus, with botanical descriptions and photos. Personal project, with about 60 families represented.
- http://utopia.knoware.nl/users/aart/

Plant Resources Center of the University of Texas at Austin
- Herbarium holding the world's largest collection of Texas plant specimens. Site offers history, and information about staff and facility use.
- http://www.biosci.utexas.edu/prc/

Caudiciforms
- Information and photos of many species of caudiciforms - plants with thickened bases.
- http://www.bihrmann.com/caudiciforms

E-Flora BC
- Electronic atlas project for the plants of British Columbia, covering life forms from vascular plants to algae, and topics from identification to scientific collections.
- http://www.geog.ubc.ca/~brian/florae/

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.
- http://npdc.usda.gov/

Kew Record of Taxonomic Literature
- Database of references to publications on the taxonomy of flowering plants, gymnosperms, and ferns.
- http://www.rbgkew.org.uk/bibliographies/KR/

Glossary of Roots of Botanical Names
- Meanings of over 1000 root words used in scientific names of plants.
- http://garden-gate.prairienet.org/botrts.htm

University of Manchester: British Flowering Plants
- Searchable, illustrated collection.
- http://emu.man.ac.uk/mmcustom/BotQuery.php

Albion College Vascular Plant Image Gallery
- Taxonomically arranged images and summaries of family characteristics.
- http://www.albion.edu/plants/

Digital Flora of Texas - Vascular Plant Image Library
- Large collection of photographs, arranged by family.
- http://www.csdl.tamu.edu/FLORA/gallery.htm

Hawaiian Native Plant Genera
- Images of hundreds of species of ferns, fern allies, and flowering plants, arranged by genus.
- http://www.botany.hawaii.edu/faculty/carr/natives.htm

Illustrated Flora of North Central Texas
- Information including keys, descriptions and illustrations of species available in Adobe pdf format by Shinners and Mahler.
- http://artemis.austincollege.edu/acad/bio/gdiggs/EastTX/ETinfo.htm

Flora of Hokkaido
- Distribution maps of vascular plants of Hokkaido, Japan.
- http://www.hinoma.com/maps/index.shtml

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.
- http://neatlas.huh.harvard.edu/

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.
- http://www.csdl.tamu.edu/FLORA/b98/check98.htm

Dictionary of Botanical Epithets
- Glossary of Latin terms used in species names, from abbreviatulus to yunnanensis.
- http://www.winternet.com/~chuckg/dictionary.html

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.
- http://plants.usda.gov/

Forestry Images - Plants
- Small collection of plant imagery, from University of Georgia.
- http://www.forestryimages.org/plants.cfm

Land Plants Online
- Southern Illinois University's guide to the taxonomic and evolutionary relations among terrestrial plants, with extensive links to other resources.
- http://www.science.siu.edu/landplants/

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.
- http://www.calflora.net/

International Plant Names Index
- Database of the names and associated basic bibliographical details of all seed plants.
- http://www.ipni.org/

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.
- http://florabase.calm.wa.gov.au/

The Oldest Land Plants
- Introduction to the first land plants, known from fossils.
- http://www.xs4all.nl/~steurh/eng/old1.html

CalFlora Database
- Searchable database all 8375 currently recognized vascular plants in California, including 20000 photographs.
- http://www.calflora.org/

Natural Perspective: Plant Kingdom
- Introduction to the Plant Kingdom with information on some of the divisions which make up this group.
- http://www.perspective.com/nature/plantae/

Names in Current Use for Extant Plant Genera
- International Association for Plant Taxonomy searchable database.
- http://www.bgbm.fu-berlin.de/iapt/ncu/genera/NCUGQuery.htm

Introduction to the Green Kingdom
- Brief introduction to the plant kingdom with links to further information.
- http://www.ucmp.berkeley.edu/plants/plantae.html