The vegetation of Krakatau and Verlaten island has in the last ten years become considerably richer, in places even luxuriant. The results of our excursion enabled us to add considerably to the plantlist of the group of islands. The present flora of Krakatau includes representatives of all divisions of the plant-kingdom : Myxomycetes, Bacteria, Algae, Fungi, Liverworts, Mosses, Ferns, Gymnosperms, and Angiosperms. The total number of species collected in the group of islands during the excursions made in 1886, 1897 and 1906 reached 137.

In the following list the species obtained on the three occasions are arranged according to families and classes, beginning with the Angiospermae dicotyledoneae. The middle column shows on which of the three islands the plants were found and when (1886, 1897 or 1906) the records were made. (Abbreviations: K. = Krakatau; V. = Verlaten island; L. = Lang island; 1 = visit in June 1886; 2 = visit in March 1897; 3 = visit in April 1906.)

The information in regard to the area of distribution of the phanerogams and vascular cryptogams is taken from the Floras and systematic works mentioned below.