This taxon name is not current. The available references for this name are:
Heliotropium argyreum Craven is more recently known as Euploca argyrea (Craven) M.W.Frohl. & M.W.Chase
Reason See M.W. Frohlich et al. in Phytotaxa 434:15 (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A taxon name that is no longer current will retain its ‘Threatened’, ‘Extinct’, or ‘Extinct in the Wild’ status until a new name has been published in a Biodiversity Conservation Order.