The participants were: The Second International Phytogeographic Excursion was a travel across North America from July to September 1913.
The participants were:[6][7] The Third International Phytogeographic Excursion was proposed in 1915, but postponed due to the First World War.
It was finally carried through in 1923 in neutral Switzerland, and as noted by John William Harshberger is his report in Ecology, the participants from Germany, France and other nations recently at war, coexisted peacefully.
The participants were, among others: The Fourth International Phytogeographic Excursion was held in Scandinavia in 1925 (July 2 to August 24).
Through the 1930s and after the Second World War, the International Phytogeographic Excursions continued at regular intervals, but now outside the mainstream of ecology.