This taxon name is not current. The available references for this name are:
Bidens subalternans DC. has been misapplied against the current name Bidens bipinnata L.
Reason See A.R. Bean in Austral.Syst.Bot.Newsletter 184:44 (2020)
See also: A longer explanation of these and other terms in our Plant Names Primer.
A taxon name that is no longer current will retain its ‘Threatened’, ‘Extinct’, or ‘Extinct in the Wild’ status until a new name has been published in a Biodiversity Conservation Order.