| Abstract: | The taxonomic status of the red algal genus Pachymeniopsis (Halymeniaceae) was evaluated based on a morphological study of the type species Pachymeniopsis lanceolata (Okamura) Yamada in Kawabata (=Aeodes lanceolata Okamura). Features used to separate Pachymeniopsis from allied genera such as Aeodes or Grateloupia were found to be inconsistently expressed within even single populations, and P. lanceolata is considered to be best placed in Grateloupia. The two remaining species, P. yendoi and P. elliptica, are judged to be conspecific, with P. elliptica also best placed in Grateloupia. The genus Pachymeniopsis is, therefore, considered synonymous with Grateloupia. The transfer of P. lanceolata to Grateloupia is proposed as Grateloupia lanceolata (Okamura) Kawaguchi, comb. nov. The reinstatement of Grateloupia elliptica Holmes, which includes Pachymeniopsis yendoi as a synonym, is also proposed. |
