A new subtribal classification of Arundinarieae (Poaceae, Bambusoideae) with the description of a new genus

Abstract

A new subtribal classification of the woody bamboo tribe Arundinarieae is proposed based on recent phylogenomic studies. Five subtribes, corresponding to the five major lineages of the ddRAD-seq based phylogenomic trees, are recognised: Arundinariinae (the leptomorph lineage), Ampelocalaminae (the ADH lineage), Gaoligongshaniinae (represented by Gaoligongshania), Hsuehochloinae (represented by Hsuehochloa) and Thamnocalaminae (the pachymorph lineage, i.e., alpine bamboos). Subtribes Ampelocalaminae, Gaoligongshaniinae and Hsuehochloinae are newly established, while the circumscriptions of subtribes Arundinariinae and Thamnocalaminae differ from the traditional classification. Subtribe Arundinariinae also includes those taxa that were previous members of the subtribe Shibataeinae. Thus, among the five redefined subtribes, Arundinariinae is the most heterogenous in terms of morphology. In Arundinarieae, rhizome type has greater implications for classification than other vegetative and reproductive characters at the subtribal level. In addition, the new monotypic genus Ravenochloa is described on the basis of its morphological characteristics and geographical distribution to accommodate the unique phylogenetic entity of Indocalamus wilsonii.