Myxochlamys (Zingiberaceae), a new genus from Borneo

摘要

A new genus and species, Myxochlamys mullerensis (Zingiberaceae) from Central Kalimantan, Borneo is described. This new species is characterized by indistinct pseudostems; congested inflorescences with spirally arranged bracts; copious, highly viscous, axillary-pooled mucus secreted from glands on imbricate bracts; and flowers with a concave labellum, versatile anthers, and a groove formed by the inner surface of the corolla tube to envelope and hold the style. Parallel orientation of the plane of distichy of the leafy shoots, well-developed staminodes, and labellum not connate with the filament suggest that Myxochlamys belongs to the tribe Zingibereae. Among the genera in Zingibereae, Myxochlamys is similar to Scaphochlamys in that it lacks a distinct pseudostem and spiral inflorescence; it is distinct from Scaphochlamys, however, in that it has a groove within the corolla tube, concave labellum and versatile anthers. Phylogenetic analyses based on DNA sequences of the nuclear internal transcribedspacer (ITS) and maturase K (matK) of the chloroplast DNA show similarity with Distichochlamys, Myxochlamys, and Scaphochlamys. The similarities and differences between Myxochlamys and related genera are discussed.