Peony flowers. 17th century artwork of two peony (Paeonia sp.) flowers (red) and stonecrop flowers (Sedum sp., lower left). Peonies are used as a sedative in herbal medicine, while stonecrops are used to reduce high blood pressure. Artwork from Basilius Besler's Hortus Eystettensis (1613). This book illustrated over 1000 flowers, attempted an early pre-Linnaeus taxonomy and was the largest and most comprehensive work of its time.