Monkshead flowers. 17th century artwork of flowers from two monkshead (Aconitum sp.) plants. Their roots are used in herbal medicine preparations for their painkilling (analgesic) properties. 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.