Yggdrasil

(Also The World Tree, Ask Yggdrasil, Hoddmimir's Wood, Laerad or Odin's Horse)

"The Terrible One's Horse"
"The Eternal Tree of Life"
"The Tree of Knowledge"
"The Horse of Yggr*"

In Norse mythology, Yggdrasil, the world tree, is a giant ash that links and shelters the nine worlds: Asgard, Ljossalfheim, Mitgard, Svartalfheim, Hel, Jötunheim, Muspelheim, Vanaheim and Niflheim. The tree itself, created many years before the earth was formed, was the giver of all life, but also symbolically important. As long as Yggdrasil stood, healthy and green, the gods would be safe from Ragnarok.

The tree is supported by three roots. One root is planted in Asgard, one in Jötunheim (where Ginungagap was once located), and one in Niflheim. Under the root that extends over Niflheim is the spring Hvergelmir. The rivers Svol, Gunnthra, Fjorm, Fimbulthul, Slidr, Hrid, Sylg, Ylg, Vid, Leiptr, and Gjoll all originate from that spring.

Under the root which reaches into Jötunheim is Mimir’s well (Mímisbrunnr), which has all wisdom and intelligence contained within it. Mimir is its guardian, and Odin paid the price of an eye for the privilege of a drink.

The root that extends into Asgard sits atop Weird’s well (Urdarbrunnr or Nornesalen, the holiest of wells). Each day, the gods ride over Bifrost, the rainbow bridge, to a beautiful hall by the well where they hold court. It is there that Weird, Verdandi and Skuld (the three Norns, the weavers of the web of fate) take water from the well and pour it over Yggdrasil to prevent it from death and decay. The water in Weird’s well is so holy as to turn everything that touches it white (the surrounding mud and the feeding swans are the color of eggshells).

There are animal inhabitants of Yggdrasil. Nidhogg, a serpent, lives under the root into Niflheim. He gnaws at the tree and, with the aid of innumerable snakes, torments the dead. Four stags (Eiktyrne, representing the four winds) also torment the World Tree: Dain, Dvalin, Duneyr and Durathror all run through the branches and feed on the leaves. Messages are delivered between worlds by the squirrel Ratatosk ("swift teeth"), and a eagle or golden cock, Vidofnir ("tree snake") sits perched on the topmost bough.

On the day of Ragnarok, Surtr, the fire-giant, will set fire to the tree, and it will be destroyed. According to some versions of the great battle, Lif and Lifthrasir (the two humans that survive Ragnarok) stay alive by hiding in the branches of Yggdrasil.

Sources:
http://www.angelfire.com/on/Wodensharrow/yggtexts.html
http://www.pantheon.org/articles/y/yggdrasil.html

I believe that Yggdrasil was originally a real tree somewhere in Europe, far back in the mists of time, which was venerated as the "axis mundi", the axis of the world. Eventually, as tribes migrated and the memory became mythology, Yggdrasil's basis in reality was forgotten and lost to posterity.

Yggdrasil is described as an evergreen tree that takes its nourishment from the Well of Wyrd. It has a hollow space inside, in which the last man and woman will be preserved at the renewal of the world. Four stags roam its branches, eating the leaves and dripping honeydew from their horns, which falls to the ground and returns to the Well. Bees make honey from the honeydew. The tree is afflicted with some kind of fungus, and the three Wyrdae/Norns must wash it with water from the Well each day to keep it healthy (the well-water is said to make the tree “white”).

Interpretation: The tree is obviously a yew tree. Yews are evergreen and are often hollowed-out inside while new living wood continues to grow around the empty centre; they are the only tree which can live indefinitely. Although it is unlikely the ancient Europeans were aware of the role aphids play in honeydew production, the “stags” may represent aphids, which suck sap from the leaves (sap drawn up from the Well-waters) and excrete honeydew, which coats the leaves of the tree and rains down in sticky-sweet drops on everything beneath. Aphids even have “horns” with which they can do battle with each other. Trees hosting aphids often suffer from “sooty mould”, a greyish-black fungus that grows on the leaves and bark when they are coated in sticky honeydew. The mould itself is not harmful, but if it becomes too abundant it can prevent adequate light from reaching the leaves and inhibit photosynthesis. The fungus can be removed by washing the tree, as the Wyrdae/Norns bathe Yggdrasil, to “whiten” it and maintain its health. Bees are attracted to honeydew and make honey from it just as they do from flower nectar.

In this context, drinking mead made of fermented honeydew becomes an indirect imbibing of the waters of Wyrd's Well. Honeydew mead is thus literally “the nectar of the Gods”, the “mead of inspiration or wisdom”, given to human beings and ingested by us as a way of participating in the cosmic, primal cycle of nourishment that begins and ends in the Well of Wyrd. Bees, and perhaps aphids, must have been seen as sacred, almost mystical creatures in the eyes of our ancestors.