Haoma is a divine plant in Zoroastrianism and in later Persian culture and mythology. Haoma has its origins in Indo-Iranian religion and is the cognate of Vedic soma.
Both Avestan haoma and Sanskrit soma derived from proto-Indo-Iranian *sauma. The linguistic root of the word haoma, hu-, and of soma, su-, suggests 'press' or 'pound'. (Taillieu, 2002) The Middle Persian form of the name is hōm, which continues to be the name in Modern Persian, Pashto and other living Iranian languages.
The physical attributes, as described in the texts of the Avesta, include:
The indirect attributes (i.e. as effects of its consumption) include:
Many of the physical attributes as described in the texts of the Avesta match the plant used in present-day Zoroastrian practice. In present-day preparation of parahaoma (for details, see Ab-Zohr), ...
According to Falk, Parsi-Zoroastrians use a variant of ephedra, usually Ephedra procera, imported from the Hari River valley in Afghanistan. (Falk, 1989)
Since the late 18th century, when Anquetil-Duperron and others made portions of the Avesta available to western scholarship, several scholars have sought a representative botanical equivalent of the haoma as described in the texts and as used in living Zoroastrian practice. Most of the proposals concentrated on either linguistic evidence or comparative pharmacology or reflected ritual use. Rarely were all three considered together, which usually resulted in such proposals being quickly rejected.
In the late 19th century, the highly conservative Zoroastrians of Yazd (Iran) were found to use genus Ephedra, which was locally known as hum or homa and which they exported to the Indian Zoroastrians. (Aitchison, 1888) The plant, as Falk also established, requires a cool and dry climate, i.e. it does not grow in India (which is either too hot or too humid or both) but thrives in central Asia. Later, it was discovered that a number of Iranian languages and Persian dialects have hom or similar terms as the local name for some variant of Ephedra. Considered together, the linguistic and ritual evidence appeared to conclusively establish that haoma was some variant of Ephedra.