The plant contains poisonous chemicals that are toxic to animals including humans, but it has also been used as a medicine. All parts of the plant contain protoanemonin, which can cause severe skin and gastrointestinal irritation, burning mouth sensation, burning throat sensation, mouth ulcers, nausea, vomiting, diarrhea, bitter taste in mouth, blood in vomit
Many cultivars have been selected for garden use eg Anemone nemorosa 'Allenii' which has large blue flowers. It has been awarded an Award of Garden Merit (AGM) H4 (hardy throughout the British Isles) by the Royal Horticultural Society, as have several of its cultivars (see below).
The RHS Plant Finder 2008–2009 lists 70 cultivars of Anemone nemorosa (AGM H4) available from nurseries in the UK. Some of those most widely available are:
- 'Alba Plena' - double white
- 'Allenii' (AGM H4) - large lavender-blue flowers, often with seven petals (named after James Allen, nurseryman)
- 'Bowles' Purple' - purple flowers (named after E.A. Bowles, plantsman and garden writer)
- 'Bracteata Pleniflora' - double, white flowers, with green streaks and a frilly ruff of bracts
- 'Robinsoniana' (AGM H4) - pale lavender-blue flowers (named after William Robinson, plantsman and garden writer)
- 'Royal Blue' - deep blue flowers with purple backs
- 'Vestal' (AGM H4) - white, anemone-centred flowers
- 'Virescens' (AGM H4) - flowers mutated into small conical clusters of leaves.
Anemone × lipsiensis, a hybrid between A. nemorosa and A. ranunculoides, has pale yellow flowers; A. × lipsiensis 'Pallida' is the best-known result of this cross. It has been awarded the AGM H4, like both of its parents.