Tim, You wrote: "So yes it is valid to call them both corms but no they aren't the same thing." It is only "valid" in the sense that different taxonomic researchers may apply the term to structures that are not homologous, and that editors allow preferences. The same is true in Araceae, where one researcher may refer to the rootstock of Amorphophallus as a tuber, while another calls it a corm. With such allowances for inconsistency, growers and botanists alike are unable to achieve a precise, common understanding of basic terms and communication suffers at all levels. Dylan