The Zoroastrian ceremony has been performed continuously and uses ephedra, which is the strongest evidence anyone has in the whole soma and haoma question because it is a practice rather than a reconstruction. But continuity of a rite does not establish continuity of a species, and substitution is documented on the Vedic side of the same inherited tradition.
What would resolve this Residue analysis of Iranian ritual vessels of Achaemenid date or earlier, compared against the ephedra of current practice.
OpenArchaeobotany with Avestan philologyMary Boyce, A History of Zoroastrianism