While we did touch upon Greco-Roman associations with trees for a few minutes in class, I think we missed a major one that ties back to Tolkien far more than the divine associations we addressed (Apollo and the laurel, Athena and the olive, Zeus and the oak, etc.). For even beyond the appearance of dryads (individual spirits of individual trees), the life of trees is set apart from human life, delineating the two in a way that is not entirely unlike Tolkien’s parameters.
For trees are alive, certainly, but alive in a way that humans cannot perceive: you cannot sit and watch a tree breathe, you cannot see a tree think, and humans are not capable of sitting still long enough to watch a tree grow. There is something unnerving about an entity that does all its ‘living’ behind your back and this anxiety is in full view in the Old Forest. The trees there are “watchful”, lending the place an oppressive air without showing direct signs of life. Their consciousness is at odds with the hobbits and frightens them in a more underhanded way than the Black Riders ever do.
Personally, Old Man Willow scares me more than Shelob, Smaug, or any other monster in the Legendarium, and I think I can pinpoint why in regards to this ‘alive without living’ paradox. We know we’re supposed to be scared of Shelob and we have good reason to be: she’s huge, she’s poisonous, she’s homicidal (or hobbit-cidal, rather) and she is in a shape that humans are accustomed to being afraid of. She operates on the same plane of existence as her prey, pursuing them physically through the caves. Old Man Willow, on the other hand, is more subtle. He lures them in, and there is something infinitely more terrifying about an enemy that makes you come to it of your own free will. Even more unsettling is the brief exchange where Pippin, who has been half consumed by the tree, is the only one who can relay its threat to “squeeze [Pippin] in two” (Fellowship of the Ring, 133). As Tom says, “his heart was rotten but his strength was green” (Fellowship of the Rings, 147): Old Man Willow’s power lies on a plane beyond human perception, as does the rest of his ‘life’. He speaks, but cannot be heard except by someone being forced into his realm of existence. He lives and plots and grows, but not in a way we can see. And if something like that means us harm, it makes it much, much harder to fight.
This halfway point, this living without visible signs of life, is where I think we skipped over an important theme in classical mythology: transformation into or imprisonment within trees. In Greco-Roman texts, this is more often than not a sort of consolation, a reprieve from life without actually dying, a transference of consciousness into something beyond the range of human perception. Daphne is turned into the laurel after she begs for a reprieve from Apollo’s pursuits. Her new form puts her beyond the reach of even an amorous god, even though “sentit adhuc trepidare novo sub cortice pectus”, “he [Apollo] still sensed her breast trembling beneath the new bark” (Metamorphoses, 555). The nymph still lives, but is now operating on a plane that makes her unreachable and alien. While it must be noted that this is not a punishment, there is still a sense of fear and anxiety surrounding the transformation in most cases, as it is only used in the most dire of circumstances. Another of Ovid’s stories concerns Myrrha, who after an incestuous relationship with her father begs for divine mercy and, rather than bear the shame of her deeds, is turned to a myrrh tree, ever weeping the sap for which the tree is prized. Again, a person is being put beyond the reach of human cares (though Myrrha still delivers her baby and Adonis is born from a cleft in the tree), leaving behind human consciousness for something deeper and slower, more akin to Treebeard’s “long, slow, steady thinking” (Two Towers, 64). However, emotion and signs of life are never truly put aside. Daphne’s laurel leaves quiver in the wind and Myrrha weeps precious tears, for though they are no longer human, even in this mythology there are always reminders that trees are alive, thinking and feeling on a level apart from the plain of human consciousness.
Perhaps closer to Tolkien’s use of the scarier sides of trees is British and Celtic mythological tree-human interactions. In several versions of the Scottish ballad of Tam Lin, the defeated Fairy Queen snaps that “had [she] known what this night [she] did see/ [She’d] have look’d him in the eyes and turned him to a tree”. This is explicitly a punishment (and a spiteful one at that) for Tam Lin has been delivered from thralldom by his lady-love and is no longer able to serve as the Queen’s ‘tithe to Hell’. However, the thread takes a turn for the worse (away from transformation and straight into imprisonment, not only a threat but a deed carried out) in Arthurian legend with Merlin’s demise.
A bit of background: in some accounts of King Arthur and his court, Merlin’s end involves being imprisoned in a tree by his student Nimue (or Ninianne, Vivianne, and a few other variations on the name besides), who has learned his secrets from him. In any case, in the version I heard most as a child, she trapped him within a tree.
Now, we’ve definitely seen that in Tolkien: Merry and Pippin bound up in the roots of Old Man Willow. But Tolkien’s version is (to me) more instinctually scary: for Nimue, the tree is a means to an end. But, as said before, Old Man Willow is the one in control of the situation in Tolkien, and his “grey thirsty spirit” strikes an intentionally dissonant chord with readers because it is something beyond mortal perception, something that we fear. We fear to be menaced by it, for we cannot fight it, and we fear becoming it, for it is too far distant from what we know.
Note: My Ovid translation is a little rough and done on the fly, please forgive any errors. It’s been a few years since I did any huge amounts of Latin, but I think I got the gist of the line.
 Fairport Convention. Tam Lin, 1969, Web.