Two new species of Swertia (Gentianaceae) from N. Sumatra

During the preparation of his ‘Illustrated Mountain Flora of Java’, Dr. van Steenis came upon some specimens of Swertia from North Sumatra, which he had collected himself on his expedition in the Gaju and Alas Lands. He could not place these specimens in the known Malesian species and gave them to me for further examination. They proved to represent two new species which both belong to section Ophelia C. B. Clarke. All cited specimens are located in the Rijksherbarium, Leiden. I am very thankful to Dr. H. O. Sleumer, who translated the diagnoses into Latin.