Revision of Muhlenbergia (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) in Peru: classification, phylogeny, and a new species, M. romaschenkoi

A taxonomic treatment, phylogeny based on analysis of six DNA sequence markers (ITS, ndhA intron, rpl32-trnL, rps3, rps16 intron and rps16-trnK) and classification of Muhlenbergia for Peru is given. Seventeen species and one presumed hybrid are recognised. Muhlenbergia romaschenkoi sp. nov. is newly described from the Río Huallaga Valley, northeast of Huánuco. The type of Podosemum angustatum [≡ Muhlenbergia angustata] clearly aligns with what we had been referring to as the hybrid between this species and M. rigida. Therefore, we adopt the next available heterotypic name, Muhlenbergia coerulea, for what we had been calling M. angustata and change the hybrid designation to M. coerulea × M. rigida. Lectotypes are designated for Epicampes coerulea Griseb., Muhlenbergia affinis Trin., Muhlenbergia berlandieri Trin., Muhlenbergia beyrichiana Kunth, Muhlenbergia elegans var. atroviolacea Kuntze, Muhlenbergia elegans var. subviridis Kuntze and Muhlenbergia phragmitoides Griseb.