Phylogeny of Muhlenbergia subg. Pseudosporobolus, including M. spatha (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) now found in Zacatecas, Mexico

Abstract

Muhlenbergia spatha, previously known only from near the type locality in San Luis Potosí, is reported from two localities in Zacatecas, Mexico. Historically, botanists have overlooked this diminutive annual. To clarify affinities of M. spatha, we present a molecular phylogeny emphasising species in M. subg. Pseudosporobolus using sequence data from two plastid markers (rpl32-trnL and rps16 intron) and nrDNA ITS. In addition, we include an updated description, illustration and discussion of the habitat of M. spatha.

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

“…Torr. ex A Gray, M.breviligula Hitchc., M.lehmanniana Henrard and M.venezuelae Luces (Peterson et al 2010b; 2018). Total aligned characters for individual regions and other parameters are noted in Table 2.…”

“…(tribe Cynodonteae Dumort.) is a diverse assemblage of 182 species represented by a single, monophyletic genus, Muhlenbergia (Peterson et al 2010a, b; 2016; Soreng et al 2017; Peterson et al 2018). Species within Muhlenbergia are morphologically highly variable and are characterised in having membranous ligules (rarely a line of hairs); paniculate inflorescences that are rebranched or composed only of primary branches; spikelets that are usually solitary but sometimes in pairs or triads, with cleistogenes (self-pollinated flowers that do not open at maturity) occasionally present in the leaf sheaths; one floret (rarely more) per spikelet that is perfect, staminate or sterile; glumes that are awned or unawned; lemmas 3-nerved, apex awned or unawned; and a base chromosome number of x = 8−10 (Peterson et al 1995, 1997, 2007a, b; Peterson 2000, 2003).…”

Drought tolerance as an evolutionary precursor to frost and winter tolerance in grasses

“…Overall, our reconstruction suggested a later origin of frost tolerance than drought tolerance (Figure 1a; Supplementary Figure 4a). Frost tolerance was not inferred as ancestral in either the BOP or PACMAD clades, but the ancestors of Pooideae, Danthonioideae and part of Chloridoideae ( Muhlenbergiinae ; Peterson et al 2018) were reconstructed as frost tolerant. The overall deeper origin of drought than frost tolerance supports the view that grasses were exposed to drought before frost during their evolutionary history (Linder et al, 2018; Strömberg, 2011).…”

A biogeographical analysis of Muhlenbergia (Poaceae: Chloridoideae: Cynodonteae: Muhlenbergiinae)

“…Earlier phylogenetic studies suggested that the Muhlenbergiinae originated in North America since numerous sister groups, that is, Allolepiinae P.M. (Peterson et al, 2010b(Peterson et al, , 2016(Peterson et al, , 2017(Peterson et al, , 2018a(Peterson et al, , 2018b. Ninetysix percent of the species within the Muhlenbergiinae are native to the western hemisphere, and more than 80% of these are native to North America (Peterson et al, 2007a(Peterson et al, , 2010b.…”

“…(tribe Cynodonteae Dumort.) is a diverse assemblage of 183 species included in a single, monophyletic genus, Muhlenbergia Schreb (Peterson et al, 2010a, 2010b, 2016, 2018a, 2018b; Soreng et al, 2017). Species within Muhlenbergia are morphologically highly variable and are characterized by having membranous ligules (rarely a line of hairs); paniculate inflorescences that are rebranched or composed only of primary branches; spikelets that are usually solitary, but sometimes in pairs or triads, with cleistogenes (self‐pollinated flowers that do not open at maturity) occasionally present in the leaf sheaths; one floret (rarely more) per spikelet that is perfect, staminate, or sterile; glumes that are awned or unawned; lemmas 3‐veined, apically awned or unawned; and a base chromosome number of x = 8 − 10 (Peterson et al, 1995, 1997, 2007a, 2007b, 2018b; Peterson, 2000, 2003, 2007b; Giraldo‐Cañas & Peterson, 2009; Peterson & Giraldo‐Cañas, 2011, 2012; Herrera Arrieta & Peterson, 2017, 2018).…”