I would live in your love as the sea-grasses live in the sea,
Borne up by each wave as it passes, drawn down by each wave that recedes;
I would empty my soul of the dreams that have gathered in me,
I would beat with your heart as it beats, I would follow your soul as it leads.
Before I begin with this poem, I need to make a note about the line breaks. Copying this down from the text source I have on hand, the poem is broken into 8 lines. However, it is a slim volume from which I copied this poem, so I think those breaks were inserted for the purpose of readability. Checking online sources, I saw two different line break schemes, one seemingly done at random, and the above, which presents the poem as four lines. I've chosen the one you see because I feel it preserves the rhythm of the poem best.
This short love poem by Sara Teasdale is about the desire to be lost in a love greater than yourself. Love here is in a simile, as being like the sea-grasses that live in the sea. Love is engulfing, huge, an essential component of life. Teasdale's narrator wants to be in perfect harmony with her love; "I would beat with your heart as it beats, I would follow your soul as it leads." This is a common theme in poetry, that of a self-emptying love, and the ocean comparisons here make it clear just how synchronous Teasdale's narrator wants to be with her love. Joined forever through ups and downs, "borne up by each wave as it passes, drawn down by each wave that recedes." Lovely imagery, and one can't help but feel the ebb and flow of the ocean in the poem's rhythm.
I was recently given a lovely gift of a volume of poetry, Annie Finch's "Measure for Measure," which organizes poems by their meter. While I generally refrain from explaining in technical detail the rhythm of poems, I'm going to make an exception here. The rhythm in this poem is what's called "anapestic." Anapestic poetry is stressed, following a patter of two unstressed syllables followed by one stressed syllable. Graphically, the shorthand for this is uu/. The "u" is the unstrssed, the "/" the stressed. The first line follows this almost exactly. "I would live in your love as the sea-grasses live in the sea." The only part of the line that isn't strictly anapestic is the iamb (two syllable foot) "grasses live" which is there to provide interest and contrast. I know this sort of analysis can be boring, but I felt this explanation helps justify my choice of line break in the text of the poem itself.