Johannes Leendert van Soest, who passed away on the 30th of October 1983 at the age of 85, was engineer and professor in electro-technics, and doctor honoris causa in natural science, mainly based on his botanical research in his spare time. He devided the Netherlands in various plantgeographical districts and was an internationally recognized authority on the genus Taraxacum. The herbarium of Van Soest, including c. 50 000 specimens, and his botanical correspondence are donated to the Rijksherbarium at Leiden. His biography written by Verschoof (1978) on the occasion of his 80th birthday has been complemented here with additional data.