Unravelling the identity and nomenclatural history of Zingiber montanum, and establishing Z. purpureum as the correct name for Cassumunar ginger

Abstract

AbstractCassumunar is a well‐known and widely cultivated medicinal ginger. Historically, many names have been applied to this species. Over the past two decades, Zingiber montanum (≡ Amomum montanum) has been mostly accepted as the correct scientific name for Cassumunar ginger in spite of numerous discrepancies between the protologue and the plants to which the name was applied. We re‐investigated the identity, taxonomy and nomenclatural history of Z. montanum, Z. purpureum and Z. cassumunar and their synonyms. We show that the correct name for Cassumunar ginger is Z. purpureum and that Z. montanum is a different species. A specimen at C previously regarded as the holotype of A. montanum is not original material, and represents Z. purpureum, which partly explains the confusion between these two names. Zingiber montanum is characterized by scarlet inflorescence bracts and flowers with labellum and lateral staminodes being dark purplish‐red, and mottled cream‐white. Unlike Z. purpureum, Z. montanum is not known in cultivation and has no known medicinal properties. Zingiber newmanii, Z. nudicarpum and Z. peninsulare are placed in synonymy with Z. montanum, expanding the distribution significantly in Southeast Asia and into China. Zingiber purpureum is readily distinguished from Z. montanum by dark red to maroon, purplish or almost brown bracts often with greenish margins, and flowers with cream‐white labellum and lateral staminodes. Zingiber cassumunar, Z. cassumunar var. subglabrum, Z. cliffordiae, Z. paucipunctatum and Z. pubisquamum are treated as synonyms of Z. purpureum. Neotypes are designated for A. montanum and Z. purpureum, and lectotypes are designated for Z. cassumunar, Z. cassumunar var. subglabrum, Z. cliffordiae, Z. peninsulare and Z. pubisquamum.