A major problem in horticulture was the lack of a consistent system of classification. The first successful attempt to establish a common nomenclature was in 1724 when 20 London nurserymen published a list of all plants grown in their nurseries. Swedish botanist Carolus Linnaeus’s Systema Naturae was published in 1735; it classified 7,700 plants by their botanic structure and gave them universally applicable two-part Latin names. From then on artists had to combine scientific accuracy with artistic skill. Many of Ehret’s flower portraits were copied by printmakers and published in the great botanical iconographies of his day. His patron Dr. Christoph Jakob Trew engaged the Haids, a distinguished family of Nuremberg etchers, to translate Ehret’s crisp, vigorously drawn paintings into printed illustrations.