The herbarium materials on which this publication is based were kindly put at the author’s disposal by the Directions of the following Institutes: (B) = the Herbarium of the Botanic Garden, Buitenzorg. (BD) = the Herbarium of the Botanic Garden, Berlin—Dahlem. (L) = the National Herbarium (Rijksherbarium), Leiden. (S) = the Herbarium of the Botanic Garden, Singapore. (U) = the Herbarium of the University, Utrecht. The author feels very thankful to the Directions of these Institutes for sending the herbarium materials on loan and thus making this publication possible.