The identity of the plant known as soma in ancient India and as haoma in the Zoroastrian tradition has, for around 250 years, exercised the wits and imagination of scores of scholars. This plant is praised in the highest terms--as a kind of deity--in both Zoroastrian and Vedic texts that date from around 1,700-1,500 BCE. It is said to provide health, power, wisdom, and even immortality. It has been variously identified by researchers...