Dr. Jacob de Vlas and his wife Johanna de Vlas-de Jong have been visiting Sri Lanka since 1977. In 2008, they published the Illustrated Field Guide to the Flowers of Sri Lanka. That book contains over 1 000 plant species that can be spotted in easily accessible places all over the country. However, plants that grow in the northern and northeastern regions of Sri Lanka were not included, due to the fact that these areas were closed until 2009. Volume 3 contains 1067 species of which 967 were not included in the first book and were photographed throughout the whole of Sri Lanka, including the northern and northeastern regions of the country. Most of them are common or less common, but the Sri Lankan photographers in particular were able to find quite a few very rare plants as well, including some that are new to the flora of Sri Lanka or indeed even to science. Approximately half of the pictures were taken by the authors, the others were contributed by Sri Lankan naturalists and photographers. By publishing Volume 3 the authors wish to contribute to the spread of knowledge of Sri Lankan plants among nature lovers, students and professionals, and indirectly to the conservation of the flora of Sri Lanka.