The Period.
This is easily the most understandable punctuation mark. It creates a full-stop wherever it is used in a work of poetry and should be used to the effect of separating thoughts that are meant to be digested one at a time.
I’ve seen it commonly used at the end of a given stanza to wrap up that stanzas central thought.
Periods can also be the most distracting punctuation mark when used improperly.