Legal Question in Intellectual Property in California

It is not legal to use copyrighted material. Even then many copyrighted material can be used in the text of "fair use". Quoting a poem is fair use generally as long as the copyrighted material is incidental and within the use of fair use.

If it were a collection of poems that were copyrighted that would violate it but if it were just quoting a poem and incidental to the collection then it would be within fair use. Try researching fair use to understand what can be used even if it were copyrighted.

Most anonymous poems can be used without violating any copyright issue.

I don't agree that "most anonymous poems can be used without violating any copyright issue" as the previous answer states. Here is an excerpt from the Copyright Act, 17 U.S.C. 302(c):

"In the case of an anonymous work, a pseudonymous work, or a work made for hire, the copyright endures for a term of 95 years from the year of its first publication, or a term of 120 years from the year of its creation, whichever expires first. If, before the end of such term, the identity of one or more of the authors of an anonymous or pseudonymous work is revealed in the records of a registration made for that work under subsections (a) or (d) of section 408, or in the records provided by this subsection, the copyright in the work endures for the term specified by subsection (a) or (b), based on the life of the author or authors whose identity has been revealed. Any person having an interest in the copyright in an anonymous or pseudonymous work may at any time record, in records to be maintained by the Copyright Office for that purpose, a statement identifying one or more authors of the work; the statement shall also identify the person filing it, the nature of that person's interest, the source of the information recorded, and the particular work affected, and shall comply in form and content with requirements that the Register of Copyrights shall prescribe by regulation."