How is the Speaker's mind described in Plath's poem, The Moon and the Yew Tree?

The first stanza of the poem depicts the mind of the speaker as an esoteric and ethereal landscape, with its own peculiar light. The speaker refers to “The trees of the mind” (2) and “The grasses” (3) as part of this interior landscape. She goes on to state that “Fumy, spiritous mists inhabit this place” (5). The subjective attachment to this inner locale is expressed figuratively in the speaker’s reference to the domicile that is associated with death and obsolescence: “Separated from my house by a row of headstones” (6). This turn of phrase develops the sense of scenery within the speaker’s mental landscape.