Numerous researchers of Haoma have suggested plants that in no way fit the feature of Haoma being identified as a tree.
Ie. Not a mushroom, nor poppy, nor ephedra fit the identity of the "Tree of Life"
"… which of the trees is the "tree of life"? Various sacred trees were known to the Semitic peoples, … But clearly the tree referred to was more than a “sacred tree''; it was a tree from whose fruit or juice, as culture advanced, some intoxicating drink was produced. The Gaokerena of the Iranians (10) is exactly parallel. At the resurrection, those who drink of the life-giving juice of this plant will obtain “perfect welfare,'' including deathlessness.
FOOT NOTE (from above) (10.) Gaokerena is the mythic white haoma plant (Zendavesta, Vendidad, xx. 4; Bundahish, xxvii. 4). It is an idealization of the yellow haoma of the mountains which was used in sacrifices (Yasna, x. 6-10). It corresponds to the soma plant Asclepias acida of the ancient Aryans of India. On the illustrative value of Gaokerena see Cheyne, Origin of the Psalter, pp. 400-439.
1911 Encyclopedia Anglicana; Volume 1: excerpt entry for ADAM (of Adam and Eve discussing the "TREE OF LIFE")