"The Wild Iris" is narrated in the first person, using the pronouns I, me, and my. The speaker addresses us, the readers, as you. But that's about all we get.
Readers should never assume that the writer of a poem is also the speaker in the poem. In every single English class Shmoop ever took, the teacher tried to hammer this lesson into our thick skull. But you have to admit, it's still tempting to assume that Louise Glück is the speaker of the poem. If you want to make this assumption in the privacy of your own home, you're free to do so. The SWAT team isn't going to break down your door and arrest you (or dock your grade).
But there are a few factors you might want to consider. For example, the poem itself contains no evidence that the speaker is a poet named Louise Glück. Moreover, the poem has no hallmarks of the confessional poetry genre—you know, that type of poem where the poet lets it all hang out, providing lots of information about his or her personal life. TMI, much?
Plus, Louise Glück has a history of getting cranky when people identify her too closely with the speaker in her poems, saying things like, "I am endlessly irritated by the reading of my poems as autobiography" (source). Ouch! Maybe we should look for a different speaker after all.
So what are the options? Well, there's the wild iris itself. Like many people, you may enjoy talking to your flowers, but presumably the flowers don't talk back (unless, of course, your name is Alice, and you hang out with a guy in a top-hat who looks suspiciously like Johnny Depp). In poetry, however, anything is possible.
We've said it before, and we'll say it again: there's a convincing argument to be made that the wild iris, the flower in the title, is the speaker of the poem. For example, all that talk about being buried makes sense when you consider that a perennial flower, such as the wild iris, dies each season, only to be reborn the following spring.
But that's not the only option. Even though the title refers to a flower, a human could still be the one doing the talking, either in this world or the next. Maybe a human speaker is contemplating a wild iris: the life cycle of the flower is relevant to the speaker's concerns, so the speaker imaginatively identifies with the flower. The concepts of "consciousness" and "voice" certainly make sense in reference to a human speaker.
Maybe you subscribe to the flower speaker theory, while your friend is sure it's a human. Which interpretation is best? Don't look at us: Shmoop refuses to referee this one (we haven't made up our own mind!), so have fun hashing it out among yourselves.