Read "Indian Acorn-Mortar" at The Eldritch Dark:
This haiku from Clark Ashton Smith (CAS) includes the non-standard word "asterick", which some dictionaries identify as a case of metathesis, where the recognized word "asterisk" can be rendered in spoken English to sound like "asterick" or "asterix".
Given that CAS had an extensive vocabulary, and was very careful with his diction, the choice of the transposed form of the verb was almost certainly intentional. So why did CAS make this particular choice?
I suspect it is simply a case of the poet seeking to maintain the flow of language in "Indian Acorn-Mortar". Even for a native English speaker, "asterisk" is a bit of a tongue-twister, and enunciating that word tends to result in an awkward hard stop at the end of the last syllable.
CAS needed a verb to activate the phrase "Lichens <something> the pestle", and his choice of a transposed form of "asterisk" retains the lucid specificity of that word while helping to maintain a more natural reading that avoids an unwanted pause in the middle of the last line of "Indian Acorn-Mortar".