⚠ Version 1.1 of The Plant List has been superseded and should no longer be used.
The new version is available at http://www.worldfloraonline.org. The new version is enhanced, using more data sources including Taxonomic Expert Networks and will be more frequently updated.
This name record (from WCSP (in review)) was not included in version 1 of The Plant List. It is possible the same name was included from a different data source, to check this you can search for Asclepias verticillata in version 1 of The Plant List.