(Required). A consensus taxonomy file produced by mothur.

(Optional). A specific function used for parsing the taxonomy string. See parse_taxonomy_default for an example. If the default is used, this function expects a semi-colon delimited taxonomy string, with no additional rank specifier. A common taxonomic database is GreenGenes, and for recent versions its taxonomy includes a prefix, which is best cleaved and used to precisely label the ranks (parse_taxonomy_greengenes).