1. The problem
Note: This paper is based upon the author's "SOMA, Divine Mushroom of Immortality ", published in 1969 in New York by Harcourt Brace & World Inc., and in The Hague by Mouton. This work is referred to in the following pages as " Soma".
Some 3,500 years ago, in the middle of the second millennium before Christ, a people that called themselves Aryans swept down from the north through Afghanistan and occupied the valleys of the Indus. They spoke an Indo-European language. They were hard fighters driving horse-drawn chariots. They sowed grain and bred cattle, horses, and sheep. They arrived on the scene with a fully developed religion, elaborate rituals performed by a tightly organized priesthood, a well-rounded complement of gods and goddesses in their pantheon, and a rich mythology telling of the doings of these divinities. They were closely related to the people who at or about the same time occupied what came to be known as the Iranian plateau, this name - Iran - being cognate with "Aryan ". Together these peoples are called today the Indo-Iranians. One of their important gods, Soma (or "Haoma" among the Iranians), was different from all the others: it was a plant as well as a god - the only plant that has been deified in human history, so far as we know-and the juice of that plant is also sometimes called Soma. The plant was mixed with water, then beaten out with stones in the course of the liturgy, the liquor filtered off and mixed with more water as well as honey or barley, and drunk right away by the priests before the end of the liturgy. According to the poet-priests the drink was inebriating and sublime.
All that we know about the Aryans at this stage of their history comes to us from a collection of 1,028 hymns that they composed after arriving in the Indus Valley and sang in the course of their worship. These hymns are what is known as the RigVeda Words and music, they were passed down to succeeding generations by the human memory, the art of disciplining the memory for this purpose having reached a refinement never equalled by any other known human society. We have no reason to think that writing was known to the Aryans at that time, although to the West of the Indo-Iranians, in Mesopotamia and the Near East, we possess numerous elaborate cuneiform texts inscribed over the preceding thousand years and more. Chief reliance for perpetuating the hymns was placed on the human memory for thousands of years until in the middle of the last century Western scholars took them down from the mouths of Hindu priests and published them. The text is settled and has been available for study for the past 120 years, but the meanings of the verses are often obscure, and, as is natural in hymns impregnated with religious terminology and beliefs strange to us, filled with allusions that evade and challenge the Vedic scholar. The language that these priests spoke is known as "Vedic", which a thousand years later developed into the Sanskrit tongue.
What was this plant that was called "Soma" ? No one knows. Apparently its identity was lost some 3,000 years ago, when its use was abandoned by the priests. The Indians were a people singularly devoid of an interest in history and seem not to have been curious about the identity of Soma. The earliest liturgical compositions of the Indo-Aryans, called the Brahmanas and put together after the hymns had been assembled, discuss the surrogates to be used for Soma in the ritual but fail to describe the original plant. The preferred surrogates were to be red, as Dr. Wendy Doniger O'Flaherty, my collaborator, has shown. There is a tradition among the Brahmans that the surrogates had to be small, leafless, and possessed of fleshy stems. Throughout the ages the surrogates have been chiefly leafless plants, species of the genera Ephedra, Periploca, and Sarcostemma. The inner circle of Brahmans have always known that these replaced the original Soma, but when Western scholars arrived on the scene these plants were among those actually considered in the quest for Soma, although they had no palatable juice. Some inquirers felt that Soma, if not one of them, must have resembled them closely. Because of the West's obsession with alcohol, all sorts of fermented drinks were also considered - barley beer, grape wine, etc. - but the fermentation process lasts too long for the juice to be squeezed out and to develop inebriating virtues before the end of the liturgy, a liturgy by the way that could be performed three times in a day. Some students have even suggested a distilled potion, forgetting that the distillation process had not yet been invented. There have been many other suggestions - rhubarb, hemp, etc. - that need not detain us because they have been advanced without conviction and fly in the face of the wording of the RigVeda hymns themselves.
2. My solution
I believe that Soma was a mushroom, Amanita muscaria (Fries ex L.) Quel, the fly-agaric, the Fliegenpilz of the Germans, the fausse oronge or tue-mouche or crapaudin of the French, the mukhomor of the Russians. This flaming red mushroom with white spots flecking its cap is familiar throughout northern Europe and Siberia. It is often put down in mushroom manuals as deadly poisonous but this is false, as I myself can testify. Until lately it has been a central feature of the worship of numerous tribes in northern Siberia, where it has been consumed in the course of their shamanic sessions. Its reputation as a lethal plant in the West is, I contend, a splendid example of a tabu long outliving the religion that gave rise to it. Among the most conservative users of the fly-agaric in Siberia the belief prevailed until recent times that only the shaman and his apprentice could consume the fly-agaric with impunity: all others would surely die. This is, I am sure, the origin of the tabu that has survived among us down to our own day.
In the English language there is now no name for Amanita muscaria, for "fly-agaric" is only a term of convenience having no circulation among country folk in Great Britain. It is an artificial designation chiefly used by mycologists writing for laymen. I first became aware of the importance of this mushroom in Europe's remote cultural history by examining the names for it in the other northern European languages. Many of these names are associated with the fly, as in German Fliegenpilz. In my book I hope I have succeeded in demonstrating that this "fly" is not the domestic fly as almost everyone in modern times has believed. Down through the Middle Ages and even later in some places the "fly" was the key to "possession", to insanity, to abnormal mental behaviour. This "fly" of mental "possession" still permeates the vocabularies of many of the European languages. The second name currently used in Northern Eurasia is associated with the toad. In the French provinces it is called the crapaudin (crapaud = "toad"), in Basque amoroto, "the toad one", throughout China the hama chun, the "toad-mushroom"; these are the names in the vernaculars. In English the "toadstool" and in other languages around the North Sea its verbal congeners with the same or similar semantic content are used to designate mushrooms that the observer rejects and shrinks from. The toad is associated with unwanted mushrooms also in Slovakia and the Ukraine, and the connexion survived in Old French: under the Christian regime le bot meant a toad, a mushroom, and Satan. To this day the fly-agaric is preeminently the "toadstool ": children are told not to touch it, adults commonly believe that they would die should they eat it. I am convinced that all names of mushrooms in which the toad is one element originally were specific to the fly-agaric. It was tabu, and following the way of objects under the blight of a powerful but dying tabu, the specific designation lost its focus and spread vaguely over all of the mushroom tribe, making them all outcasts. In pagan times the toad was a friendly chthonic divinity and up until recently it survived in that role in remote parts of Lithuania where Christianity was the last to triumph over paganism, as Maria Gimbutas, the distinguished pre-historian and herself a Lithuanian, has told us.
3. The evidence
When I approached the Soma problem on going to the Far East in 1963, I did so in a despairing frame of mind: where so many others had failed, who was I to succeed ? I knew no Vedic nor Sanskrit. Fortunately Louis Renou, one of the leading humanists and scholars of his generation, had just translated three quarters of the RigVeda into French. His rendering is intended for scholars and is as literal as he could make it. I read what he had translated, as well as all that he had written on the RigVeda in the previous 15 years, and all other available Vedic commentaries. I enlisted the co-operation of Dr. Wendy Doniger O'Flaherty, a Vedic scholar, who worked with me and struggled with the questions that came up in the course of our task.
It seemed to me apparent that all alcoholic drinks could be eliminated at once. This was not only because of the time element in completing the fermentation process: the descriptions of the effects of Soma could never have been written after drinking alcohol. Soma must be an hallucinogen. I was struck quickly by a singular fact: there is no mention of the roots, the leaves, the blossoms, or the seed of Soma in the hymns of the RigVeda. The whole of the RigVeda is permeated with Soma and one of the ten books of the RigVeda is wholly concerned with the Sacred Plant. These hymns were written over generations, perhaps centuries, by poets in different cultural centres of the land. Given the freewheeling nature of the poetic mentality throughout cultural history, it was unthinkable that scores of poets scattered far and wide and living over centuries could praise a chlorophyll-bearing plant without once mentioning these essential parts of that plant's organism. Ergo: the plant had neither roots, nor leaves, nor blossoms, nor seed. What plant answers the need ? The whole of the fungal world.
Time and again the poets of the RigVeda speak of Soma as growing on the mountain heights. For me this meant a plant that in the northern forest belt would grow at or dose to sea level but that in the latitude of the Indus Valley would be found only high in the mountains, where climatic conditions would support the vegetation of the temperate zone.
Naturally I had not gone this far before my thoughts gravitated to the fly-agaric of northern Eurasia. The Aryans had come down from the North, no one knew from where. Had they perhaps shared in the cult of the regal fly-agaric ?
The reader of the RigVeda must know that he is reading poetry and be prepared for figures of speech and flights of analogy that bespeak poetry. If he grasps the imagery of the poet, he will perceive at once that the poet, in speaking of Soma, has the fly-agaric in mind. In the synopsis that follows I cannot do justice to this imagery. In my book I supply coloured photographs illustrating lines of the RigVeda; here I list a few of the turns of phrase that I there illustrate and expound. The reader must use his imagination and he then will grasp the idiom. To the unique natural beauty of the fly-agaric (ignored in the West) was added the awe that goes with a plant having hallucinogenic powers: the beauty and the awe enhance each other in the mind of the Vedic poet.
Soma in the RigVeda is dazzling, flaming, brilliant, resplendent, lustrous. The same adjective is repeatedly applied to it as to the steeds of the Sun-god racing across the sky. This fits the fly-agaric like a glove. Its juice is described as tawny yellow. The juice of the fly-agaric is also tawny yellow. Soma for the poets is the Fireplant, the Sun-plant. The fly-agaric when it first appears is a fluffy egg-shaped ball, brilliantly white. It breaks its envelope and rises on its stem expanding its brilliant red umbrella-cap, flecked with the remains of the white envelope. Says the RigVeda: "He abandons his envelope, goes to the rendezvous with the Father. With what floats [ i.e., the remnants of the envelope] he makes continually his vesture-of-grand-occasion."  A perfect figure of speech ! The fly-agaric is constantly compared with the sky, the vault of heaven. "With his thousand studs he conquers mighty renown," the studs being the white patches on the pileus. "The hide of bull, the dress of sheep." The cattle of that day seem to have been red; the dress is the white woolly patches left by the original envelope. "By day he is the colour of fire, by night, silvery white." By day one sees the red cap, by night the colour becomes undistinguishable and one sees the silvery white of the disintegrating veil. There is much talk of the "udder" of Soma. I interpret this as the full-blown red pileus of the fly-agaric, which has the shape of an udder. In many languages instead of the "cap" of the mushroom people speak of the "head "; so the RigVeda, time and again. The stalwart fly-agaric is often referred to as the "pillar" of the world, or the sky. The hymns must be read as poetry and as the poet would view the fly-agaric: "pillar" is an apt metaphor, when you consider the role of fly-agaric in the psyche of the priests. The poet speaks of the "single eye ". This has baffled Vedic scholars, but my explanation makes it clear: the fly-agaric does not grow in pairs, and each fly-agaric is, cosmically speaking, a single eye contemplating the universe.
Then there is the matter of the filters. We have already spoken of one filter, through which the juice of the crushed plant is passed. This is the second filter. But there is the first filter that has confused the scholars. The divine beverage descends from heaven on the rays of the sun and enters the plant filtered by the sun's rays which are caught and held on the vault of heaven, i.e., the skin of the plant. This is a poet's elaborate conceit for linking the inebriating juice with the sparkling spots on the surface of the pileus.
There is mention of a third filter, and this brings me to my suggestion that has aroused the most resistance. In the Northeast of Siberia the tribes take the fly-agaric straight, and they also drink the metabolite of the fly-agaric, the urine of the person who has eaten it. Some say the metabolite is superior to the original plant, perhaps because the human organism may filter out - i.e., "the third filter" - nauseating ingredients and isolate in the urine only the inebriant. At any rate, the practice is well attested by numerous witnesses. Imagine then my surprise, when I read in the 4th verse of the 74th hymn in the 9th book that the officiating priests with full bladders urinate the on-coming Soma! This verse comes precisely at a point of peculiar intensity in the hymns, where it might be expected that the Holy-Mystery, ordinarily not mentioned, would be spelled out in words for all to hear. Though both Renou and Geldner, who has also translated the RigVeda into German, agree with this rendering, the meaning has not been clear. My reading of the passage makes sense but arouses visceral resistance in Western scholars, as well it might. Though there is only one overt passage in the RigVeda that refers to the Soma-urine, we find supporting evidence in the Avesta, the bible of the Zoroastrians, in a verse where Zoroaster excoriates the priests who evilly delude the people with the urine of drunkenness. This verse now is clothed with meaning for the first time. The Parsees, descendants of the Zoroastrians, drink bull's urine in their rites to this day. The Manichaeans, who inherited the main tenets of their religion from the Zoroastrians, survived in China until the 12th century, and in that century an unfriendly official of the Chinese government reporting on their activities complained that in their religious rites they consumed too many red mushrooms and performed ablutions with urine, apparently human urine. Even more striking is an episode in the Indian epic, the Mahabharata: Uttanka a holy man had been promised a boon, and he has contented himself with asking that whenever he was thirsty, drink would be supplied to him. The god Krishna agreed. Some time later Uttanka was thirsty in the desert and he wanted water. Krishna appeared from nowhere in the disguise of a naked filthy outcaste, a hunter, surrounded by scavenger curs. This hunter urinated and offered Uttanka his urine to drink. Uttanka, aggrieved, naturally refused with indignation, only to be told a little later by Krishna in his own person that what he had been offered was Soma-urine! Had he accepted the urine of the outcaste, he would have joined the Immortals.
Western scholars have resisted my role for Soma-urine: one of them has called it a " surprisingly novel interpretation ". But since my book came out I have received a letter from India saying that at last I have provided an explanation for a custom that survives to this day. The sadhu or Holy Man sitting among his adoring disciples, chelas, will grant a favoured disciple the privilege of drinking his urine, and thus convey to the disciple some of his own spiritual powers. My informant supposes that this practice, taken for granted in India, comes down from Vedic times when the potent metabolite of Soma was passed on to be drunk by the favoured ones.
4. Where the search for soma went wrong
Why has not Soma been identified before now? If we look into the history of Vedic studies in the West, I think we find the reason.
When this priceless treasure house of early religious poetry was first uncovered in the West in the middle of the 19th century, scholars took it in hand and worked on it to arrive at its meaning and its implications. There developed a specialty, the field of the Vedists, men who concentrated on the RigVeda. They included scholars of the highest eminence, but they were a rather closed group exploring a remote world. They sought the answer to the Soma enigma within the terms of their own discipline, in mythological and ritualistic concepts. They seem to have felt that Soma could be defined in mythological propositions. Abel Bergaigne, the French scholar, subtle and brilliant in all his perceptions, elaborated a theory that Soma was the equivalent of Agni the god of fire; Soma and Agni were interchangeable. The German Alfred Hillebrandt thought Soma was the equivalent of the moon. And so on. The world of scholarship has not accepted any of these notions, though one who seeks can find a rationale behind each of them. There was no one to insist that the identification of Soma the plant was primarily a botanical problem, that it should be put up to the botanists, the Vedists serving only to translate the relevant verses of the RigVeda and to supply alternative readings where such readings seemed permissible. The Vedists did not demur when they found themselves face to face with a botanical question: they tackled it single-handed. This was their error.
Toward the end of the last century a number of Vedists not of the first rank brought out translations of the RigVeda. These renderings were intended to convey to cultivated circles in the West the high quality of the poetry uncovered in India, the holy hymns of the Hindu religion. Their translations were pitched to please the Victorian appetite for poetry, and read like second or third-rate Tennyson. Innumerable passages that defied translation or that would shock the sensibilities of the refined reader were glossed over with vague "poetical" verses.
No botanists seem to have learned Sanskrit, much less Vedic, but they had the illusion of being in contact with the poets of the Vedic hymns by reading these translations. From these translations they could make nothing of Soma. The Soma of the hymns might indeed have been a mythological concept, so far as the translations were concerned. Many others, Hindus and Westerners, intruded into the discussion aimlessly, without bothering with the RigVeda, venturing unsupported guesses.
I think no mycologist volunteered to examine such evidence as was available and to express an opinion.
The world of the hallucinogens was not yet a special field of botanical study. By severely limiting the field of inquiry to the hallucinogens, the inquirer reduces the scope of the problem to manageable dimensions.
Now that botanists possess two translations of the RigVeda - Renou's and Geldner's - that reflect, as accurately as contemporary scholarship permits, the literal meaning of the verses, for the first time the botanists are able to perform their proper function.
5. The Tree of Life and the Marvelous Herb
If Soma, the plant celebrated in the hymns of the RigVeda, was the fly-agaric, a number of questions suggest themselves. "How could the Vedic priests-be so familiar with the plant when they were living in the hot plains of the Indus Valley where it does not grow ?" But it is at home in the nearby mountains where the birch and the conifer abound and this usually would be not more than a week's walk away, more often less. It has always been the practice in India for the young aspirant to the priesthood to retire into the jungle or forest with his teacher, and there learn the hymns, words and music, and every minute detail of the liturgy. In the Indus Valley it would not be hard, in fact it would be inviting, to climb to the birch and conifer level and there in the appropriate season, between the long spells of priestly drill, observe the life cycle of the divine plant. Later, if the pupil became a priest-poet, he would make use of his observations in composing his hymns.
Or again someone may ask: "If the fly-agaric had to be given up, why was not another species of mushroom selected in its place ?" This question assumes that the priests would wish to perpetuate the memory of the real Soma. The same fallacy afflicts the thinking of those who approach the problem from the other end: they see an Ephedra or Sarcostemma being used in later centuries as a substitute and ask whether the original plant must not have been a climber like them. These facile notions fail to allow for the circumstances that must have precipitated the abandonment of the sacred plant. In those days no mushroom lent itself to cultivation and only a finite quantity of fly-agaric was available in a given year. If because of wars or a shortage of rain there was a scarcity of supplies, a surrogate would have to be employed in the sacrifice. Such a surrogate, though its use was regrettable, must have been recognized as necessary. But when the Aryans spread out from the Indus Valley down the Ganges, and from the Ganges to the South conquering all of India, the logistical problems became at last insuperable. This must have precipitated a traumatic crisis in the history of the Aryans and their religion. Whether to abandon or not to abandon Soma, that was the question. The difficulties of provisioning the teams of priests all over the land were constantly mounting. When, around 1000 B.C., the Sacred Plant was given up for good, the priests would realize that another mushroom would present the same problems in logistics as they had faced in the past. "Anything rather than another mushroom" the priests must have exclaimed with vehemence. More-over, to choose a mushroom among the exotic fungal flora of the new subcontinent that they were conquering would have been a tricky business that even today might daunt the mycologists.
But there were reasons of greater reach why the priesthood could not allow the memory of the fly-agaric to survive, why they had to do all in their power to make the people - priests and laity - forget the image of the regal fly-agaric; in short, why they chose creepers as the permanent surrogates for the flaming mushroom. If the memory of the fly-agaric survived, there would always be competition between the genuine plant and the surrogate. Wealthy patrons, well-placed teams of priests, would perform the sacrifice with A. muscaria, the disadvantaged would have to make do with the surrogates. A black market would spring up, scandals in the church would break out. It would have been easy to perpetuate the memory of the authentic Soma, had this been the desire of the priesthood. But no, a Trappist Rule of Silence came to be imposed. The early liturgical books known as the Brahmanas contain no hint of a description of the real Soma and in fact some have seen in them positive evidence of mystification. The Sun-plant became the Moon-plant and an elaborate myth of the Moon and Soma sprang up.
In the past the identification of Soma was left to the Vedists, as we said before. They have seldom gone afield to northern Eurasia to see what light the cultures of that vast area might shed on their problems. Only now, in the past twenty years, have literal translations of the RigVeda appeared in French and German that permit non-Vedists to know, with fair certainty, what the hymnologists were saying.
Among many of the Siberian tribes that in historic times have used the fly-agaric in their shamanic ceremonies the name of the fly-agaric is also the word for "inebriate". The primary meaning is "fly-agaric", and" inebriate "is its natural extension, but the secondary sense is so old that no native associates the two words together. Thus when a native sees a Russian drunk on alcohol he says that man is "bemushroomed ", just as we would say of a man under the influence of mescaline, that man is "drunk ", although he has not drunk an inebriant. It seems that over a vast belt of Siberia the inebriant uppermost in the minds of the natives has been, not alcohol, but the fly-agaric. There are grounds for thinking this usage goes back thousands of years.
Throughout the forest belt of Siberia the tribes all revere the birch, with the conifer coming along afterwards. The birch is preeminently the tree of the shaman. He builds his hut around a bole of birch, he cuts notches in it, in his shamanic rites he climbs the birch to" travel" to the land of departed spirits. In different tribes there are individual ways in which this reverence is expressed. Many observers have asked why the birch is thus singled out, but no confident reply has been given. It seems that not one of the observers knew of the tie that binds the fly-agaric to the birch. The marvellous mushroom grows in mycorrhizal relationship to the birch, and I am confident that that is the explanation. In SOMA for the first time I draw attention to this intimate relationship and thus explain the reverence felt for the birch.
Those who have explored the legends that attach themselves to the birch in Siberia report, to their surprise, that they are all variants of one myth. The spirit of the birch is a middle-aged woman who emerges to her waist from the roots. She is grave, with flowing hair, and her breasts are full. The man who approaches her asks for drink, and she gives him her breasts. He is replenished and his strength increases a hundred-fold. There is the legend that a pool of marvellous water, the water of life, lies among the roots under the ground; this water is yellowish white. These stories seem to me to be intimately related to the Soma of the Aryans. The woman's breasts are the full-blown fly-agaric, the "udder" of the RigVeda; the milk that she gives is the juice of the fly-agaric, the pavamana of the RigVeda; the pool of the Water of Life, tawny yellow, is the source from which the fly-agaric draws its miraculous strength. The birch is the Tree of Life, the Axis Mundi, the Pillar of Heaven, and the fly-agaric is the Marvellous Herb.
In the lands from Palestine to Mesopotamia and Iran the birch does not grow, and the fly-agaric is rarely seen. But these lands were settled by peoples from the north, the Sumerians. the Hittites, the Mitannians, and last of all the Indo-Iranians. The Semitic peoples lived in intimacy with the Sumerians in Mari and elsewhere and borrowed much of their mythology from them. What in Siberia had been legends closely tied to the familiar birch and the fly-agaric became in these latitudes fabulous stories of a miraculous herb growing under a mythical Tree of Life, and protected by the Serpent. Gilgamesh, the hero of the Sumerian epic, a thousand years and more before the Aryans settled in the Indus Valley went on a quest for the miraculous herb, which at last he found only to have it wrested from him by its guardian the Serpent. In the Bible the story takes a different twist: the Serpent offers the herb to Eve and she to Adam, but there are the three essential props in the legend, the Tree of Life, the Marvellous Fruit of the Tree, and the Serpent.
Until now Soma has been regarded as peculiar to the RigVeda, with its single sibling the Haoma of the Iranians and without parentage. If I am right, I have succeeded in integrating it with the cult of a Tree and of a Mushroom that reached from one end of Eurasia to the other and back in time to the distant reaches of the Stone Age.
The inscribed seals of the Mohenjo Daro-Harappa civilization in the Indus Valley, which preceded and perhaps was destroyed by the Aryans, have defied decipherment, at least until lately, when a Finnish team may have found a clue to their meaning through an ingenious use of a computer.
See SOMA, part II for Dr. O'Flaherty's "Post-Vedic History of the Soma Plant "; the reference to the colour of Soma is on p. 97.
Note by the editor: The attention of mycologists is drawn to this novel and even sensational interpretation made by the author of Amanita muscaria's reputation for toxicity, and his claim to have eaten it with companions on several occasions without suffering ill-effects.
I relied chiefly on Louis Renou: Etudes vediques et panineennes, Tomes I-XVII, published by the Institut de civilisation indienne de l'Universite de Paris, 1955-1969, hereinafter referred to as EVP. The depository is E. de Boccard, 1 rue de Medicis, Paris 6e. We also consulted Karl Geldner: Der Rig-Veda, published in Harvard Oriental Series, Vols. 33-35. This translation is complete whereas Renou lacks most of the hymns to Indra and a few others.
SOMA, pp. 36-37; also Plate II.
SOMA, pp. 37-39; also Plate IV. The quotations are from RigVeda Books 1 and 9. Here and elsewhere the translations are based on EVP, occasionally modified slightly by Dr. O'Flaherty.
SOMA, p. 36; also Plate III.
SOMA, p. 39; also Plate V.
SOMA, p. 40; also Plate VII.
SOMA, p. 52; also Plate XII.
SOMA, p. 41; also Plate IX.
SOMA, pp. 41-42; also Plate VIII.
SOMA, p. 43.
SOMA, pp. 45-46.
SOMA, pp. 47-48; also Plate XI.
SOMA, pp. 46-47; also Plate X.
SOMA, pp. 51 ff.
In the Avesta, Yasna 48.10.
SOMA, pp. 71 ff.
SOMA, pp. 33-34.
SOMA, pp. 164 ff.
The place of the birch in the forest belt of Siberia pervades all the writings of folklorists and anthropologists of that region. In SOMA, p. 212, footnote 1, I list the easily accessible sources and in the text I summarize them on pp. 211 ff.