Genomic data resolve phylogenetic relationships of Australian mat-rushes, Lomandra (Asparagaceae: Lomandroideae).

Lomandra is the largest genus in Asparagaceae subfamily Lomandroideae and possesses economic, ecological, and ethnobotanical significance in Australia. Lomandra comprises four sections, L. section Capitatae , L. section Macrostachya , L. section Typhopsis and L. section Lomandra, the latter comprising series Lomandra and series Sparsiflorae , all recognized based solely on morphology. In this study, phylogenetic relationships were estimated for 79 Lomandroideae individuals, including 45 Lomandra species and subspecies (c. 63% of species and subspecies diversity). We generated genome-scale plastome sequence data and used maximum likelihood and Bayesian inference criteria for phylogenetic estimation. Lomandra was non-monophyletic, with Xerolirion divaricata nested within it. Two major clades were recovered: Capitatae–Macrostachya (CM) and Lomandra–Typhopsis (LT). The CM clade included a monophyletic Lomandra section Capitatae with a base chromosome number x  = 7, and L. section Macrostachya (x  = 8); the LT clade included L. sections Typhopsis and Lomandra , both x  = 8. Section Lomandra series Lomandra and series Sparsiflorae were both recovered as non-monophyletic. Morphological characters were assessed to identify combinations of characters that characterize clades. A base chromosome number of x  = 8 was plesiomorphic for Lomandra. The largest number of Lomandra species occupy the Mediterranean ecoregion and occupancy of sclerophyll vegetation was reconstructed as ancestral for the genus. [ABSTRACT FROM AUTHOR]