Stolonochloa, a new Australian genus segregated from Panicum (Poaceae: Panicoideae: Paniceae: Boivinellinae) based on phenetic analysis of morphological data

Abstract

The genus, Stolonochloa is described and two new combinations Stolonochloa lachnophylla and S. pygmaea are segregated from Panicum s.s.. Differentiating morphological characters for the new genus are compared with other genera of the subtribe Boivinellinae. Phenetic analyses showed Stolonochloa has closest morphological similarity to Entolasia and Ottochloa in the Australian Boivinellinae but differs by characters including inflorescence type, indumentum on the apex of the upper lemma, papillae on the upper floret, and anatomy of the inflorescence culm. Stolonochloa differs from Panicum s.s. by having C3 photosynthetic pathway and several other characters. The consistency of results from multiple cluster analyses was evaluated by comparison with results from analyses of a baseline dataset that consisted of scores for 133 morphological characters and 18 species, representing seven putative Australian genera from subtribe Boivinellinae, and three species of Panicum s.s. The analyses included variations in the composition of the dataset in terms of sample size, subsets of the baseline character set and character format, and the cluster algorithm including ordination and classification, and two association measures.The process used permitted recognition of morphological similarities and differences necessary for descriptions, keys and natural groups as part of alpha and beta taxonomy.