Merxmüller's interest in botany was noticed at an early age by his mentors, and he was encouraged to collect in the Bavarian Alps and countryside.

At 17 he joined the Bavarian Botanical Society and at the end of World War II was awarded a scholarship by the Maximilian Foundation, enabling him to study biology at the University of Munich.

Compositenstudien I (1950), an analysis of the collections of Sigmund Rehm from South West Africa, the Transvaal, and the Cape Province, was the first of 11 volumes, the last published in 1984.

Heinrich Nothdurft worked at the State Institute of Applied Botany in Hamburg, and collaborated with Merxmüller and Kräusel on "Sträucher und Bäume".

All had a share in the success of the Kronen-Verlag and the implementation of Erich Cramer's original idea - bring together prominent natural scientists and distinguished artists to create a unique work depicting the exact form and colour of each species, while reflecting its diversity and aesthetic beauty.