Iris' Garden - Gardener in the Netherlands presents a photo of this plant, with basic horticultural information. (1 photo)
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 4-8) (3 photos). Also a page for 'Saphirsprudel'.
Rainy Side Gardeners - Plant profile compiled by two gardeners in the Pacific Northwest. Includes propagation and pruning methods, and commentary. (zone 4-9) (1 photo)
Rob's Plants - Plant profile with basic horticultural information and often personal observations. (1 photo)