薬草
The majority and the most valuable of his works are on botany. Foremost among them are his: "Genera Plantarum" (1831–1841), in which he lays down a new system of classification; "Grundzüge einer neuen Theorie der Pflanzenerzeugung" (Foundations of a new theory of plant breeding; 1838); and "Die Medicinalpflanzen der österreichischen Pharmakopöe" (Medicinal plants in the Austrian pharmacopoeia; 1842).