Given the nature of the poem, I think that the descriptions have to be different than one another. The reality is that the poem is one of nostalgia, a feeling in the present that the past's significance is something missing in the modern setting. The lens of nostalgia is what colors the speaker's perception of the tree in the modern setting. The description of the tree in lands far off is significantly different than what was experienced because of the reality that what is present now is a reality that is not able to encompass the meaning of the tree from the past. The tree's laments and cries of pain is what makes the tree different from then and now, a description that embraces the nostalgic view of the tree and what it comes to represent to the speaker. In this, the tree's power and significance is one driven by the tendency of nostalgia and the idea of how our past is something not to return. The difference in descriptions also bring to light how the elements in our present that can link us to our past are beyond precious as they enable us to reach back into a period of time that has long since passed. For the speaker, the description of the tree's laments and cries are significant to the extent that the tree will no longer be able to serve in the present the function it served in the past. The differences in description highlights the importance of nostalgia, a condition that makes life in the present more bearable with the understanding of a past increasing in significance and meaning.