Dave's Garden PlantFiles - Profile page with horticultural basics, and member-contributed photos and comments. (zone 3-6)
Illinois Wildflowers - Informative illustrated page with description and cultivation details, also covering range and faunal associations. (3 photos)
Lady Bird Johnson Wildflower Center - Plant description and characteristics with notes on distribution, culture, and propagation. (8 photos)
Missouri Botanical Garden - Plantfinder page for one of the plants growing at the garden, with usually one or more photos, horticultural information, and noteworthy characteristics. (zone 3-6) (4 photos). Also a page for 'Whitespire'.
Trees and Shrubs Online - Reference page curated by the International Dendrology Society with descriptive characteristics and horticultural notes. (5 photos)
Virginia Tech Dendrology - Factsheet with botanical characteristics and photos of various features. (6 photos)
(3 photos)