Aspidosperma helstonei Van Donselaar, a new species of the Apocynaceae, does not show close affinity to any other species nor matches any of the nine series distinguished by Woodson (1951) in his interim revision of the genus. It was collected in a very limited area in Surinam, now forming part of the artificial Brokopondo-lake. A description of the wood anatomy, by Dr. A. M. W. Mennega, is added.