⚠ Version 1 of The Plant List has been superseded.
This name is in version 1.1 of The Plant List, record kew-2616684, with some changes.
This name is a synonym of Asclepias cryptoceras S.Watson.
The record derives from WCSP (in review) which reports it as a synonym with original publication details: Rep. Exped. Rocky Mts. 2: 317 1845.
Full publication details for this name can be found in IPNI: urn:lsid:ipni.org:names:93864-1.