Ephedra belongs to the pine family and pine is aromatic enough to produce pine-oil, an essential oil regularly produced commercially. That ephedra also is aromatic can be understood from the following incidence. Messers Marker Alkaloids, Quetta, manufacture ephedrine from ephedra plants. Their former Chief Chemist was Dr. Wright who approached Pakistan Council of Scientific and Industrial Research, when I was a member of its staff. It was found at Quetta that the mother liquor, after ephedrine extraction, to be fairly aromatic. They wanted to see its essential oil recovered in some way. However, it was realized that the mother liquor, although fragrant, did not contain sufficient concentration of essential oil to repay the cost of isolation. The above information does imply that if Soma was ephedra, it must be fragrant. We now turn for confirmation in Rigveda.
RV. 9.97.19 "Sweet-scented flow on for gain of strength that conquers heroes." Kapadia (1959) gives the word Surabhia (on p.40) as the Sanskrit for it. RV.9.107.2 "Flow hither through the fleece inviolate and most odorous." Kapadia (on p.40) has the word. Surabhintara as the original of odorous. 9.97.14. Swelling with milk abounding in sweet flavours urging meath-rich plant thou goest onward." Miss Mulholland (1976,50), interprets verse, 9.10.11, as also 9.98.12, implying an odorous principle, which I hesitate to confer. Likewise Kapadia refers to 8.1.26 as suggesting pleasant to smell when it merely speaks of "savoury soup", tasty, not necessarily fragrant. Moreover Miss Mulholland believes "Soma was a volatile oil." However she is not able to indicate what the plant could be and as such, both the plant and its active principle remain hypothetical.