Old Yew, which graspest at the stones That name the under-lying dead, Thy fibres net the dreamless head, Thy roots are wrapt about the bones.
The seasons bring the flower again, And bring the firstling to the flock; And in the dusk of thee, the clock Beats out the little lives of men.
O, not for thee the glow, the bloom, Who changest not in any gale, Nor branding summer suns avail To touch thy thousand years of gloom:
And gazing on thee, sullen tree, Sick for thy stubborn hardihood, I seem to fail from out my blood And grow incorporate into thee.
Tennyson now addresses an old yew tree that grows over some headstones. Its roots are wrapping around the dead man's head and bones—creepy.
The seasons will allow the tree to flower again, while the clock counts the hours of puny men.
There's a neat juxtaposition here between the longer natural cycles of the tree and the shorter years of men.
Are you starting to get the sense that Tennyson is really emphasizing how puny mere mortals are in the face of not only God, but also nature? Not even the wind or the sun can do much damage to the tree, which will live for a thousand years.
Now Tennyson's using apostrophe to address the tree, speaking directly to it with the super-dramatic Victorian "O."
He continues to address the tree, personifying it by calling it "sullen."
This is a great example of pathetic fallacy, where a writer describes the outside world in a way that reflects his/her own inner mood.
After all, a tree can't really be "sullen" or "stubborn," but we get the sense that Tennyson can, since he's so sad over his friend's death.
And he's grieving so much that he loses the sense of himself and grows bodiless ("incorporate") into the tree. This isn't happening for real, of course. It's just the speaker imagining being one with the tree. Far out, man.