This taxon name is not current. The available references for this name are:
Medicago polymorpha var. brevispina (Benth.) Heyn is more recently known as Medicago polymorpha L.
Reason See National Species List. https://biodiversity.org.au/nsl/services/instance/apni/751035 [accessed 06/09/2016]
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A taxon name that is no longer current will retain its ‘Threatened’, ‘Extinct’, or ‘Extinct in the Wild’ status until a new name has been published in a Biodiversity Conservation Order.