Features a searchable, multilingual garden plant encyclopedia, with a summary of cultural and botanical information and in many cases photos.
BackyardGardener.com: Garden Guides on Plants
Starting point for information on (types of) plants, with summary information for many species and varieties.
Cal's Plant of the Week
Features a new plant every week, with photo, description, and cultural information. Previously featured plants can be selected by botanical or common name. Focus is on plants for greenhouse culture.
Chicago Botanic Garden: Ornamental Plant Development
Provides access to plant evaluation reports from the Botanic Garden's plant trials. Each report, in PDF format, provides several pages of description and photos.
Dave's Garden: PlantFiles
Database with over 80,000 plants with cultivation information and pictures supplied by member gardeners.
This resource for gardeners in the Denver metro area includes a sizeable database of plants with photos and cultural information.
Features searchable database of thousands of plants, with basic information and often photos. Includes many succulents, herbs, and tropical fruit trees.
Dinosaur Garden Plants
Describes plants that lived during the age of the dinosaurs, with brief information, lists, and links to other resources for plants of the mesozoic era.
The Families of Flowering Plants
Offers descriptions, illustrations, and identification retrieval.
Garden plant finder. Searchable by garden conditions and design requirements such as flower color, size and growth habit. Search results include plant photo and summary information.
Features hundreds of plant portraits, each illustrated with several photos, documenting the garden uses and cultural requirements of each species or cultivar.
Flowers of India
Collection of hundreds of plant photos with brief descriptions. Each of the plants grows in India, but both natives and non-natives are featured.
All America Selections Winners
Showcases new varieties of flowers, vegetables, and plants for garden performance.
Guide to growing and caring for houseplants, vegetables, trees and shrubs. Also features common pests and a miscellaneous section. From the University of Saskatchewan Extension.
Offers a weed listing for the United States regions, primarily weeds occurring in lawns.
Horticopia On-line Plant Information
Includes directory of plants, categorized by genus, includes summary cultural information and small photograph for each plant.
Horticultural database with over 100,000 species and cultivars. Comments, ratings, and photos for many varieties supplied by members of the Gardenweb community.
Illinois' Best Plants
Chicago Botanic Garden provides a database of recommended plants for Illinois gardens, from perennials to trees, with photos and information on their culture and use.
Pacific Northwest Plants
Database on plant identification, culture and usage for the U.S. Northwest, including native and introduced species and their major varieties and cultivars.
Gardener Mark McDonough presents horticultural musings and illustrated plant studies, with particular emphasis on alliums and other bulbs for rock gardens.
Plants For A Future
Resource centre for rare and unusual plants, particularly those which have edible, medicinal or other uses. Offers a plant database, and various articles on gardening, perennials, and habitats.
Plants National Database
Online USDA database of botanical information, images, and links on plants in the USA, including crops and invasives. Search by name, geographic distribution, or other characteristics.
Includes information about plants native to southern Africa, including hundreds of alphabetically arranged plant portraits, by the National Botanical Institute of South Africa.
Plant encyclopedia featuring photos and short descriptions of annuals, perennials, shrubs, and trees.
A South African flower, plant and gardening portal with searchable plant database, photographs and information.