* Nature poetry: It focuses on the beauty and majesty of trees.
* Lyric poetry: It expresses the speaker's feelings and thoughts about the subject.
* Free verse: Although not completely free verse, it deviates from traditional rhyme schemes and meter.
While it is sometimes categorized as a pastoral poem due to its focus on nature, it doesn't fully fit the typical characteristics of the pastoral genre.
Overall, "Trees" is primarily considered a lyrical, nature poem with elements of free verse.