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.

Extensive 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.

Database of detailed descriptions and growing tips for thousands of plants, including many not commonly grown. Profiles include cultural information, assessment of landscape value, and photos for most.

Offers a weed listing for the United States regions, primarily weeds occurring in lawns.