Polyploidy, infraspecific cytotype variation, and speciation in Goldenrods: The cytogeography of Solidago subsect. Humiles (Asteraceae) in North America

Polyploidy is an important evolutionary mechanism in plants, and in some genera (e.g., Solidago in Asteraceae) it is particularly widespread and is hypothesized to have played a major role in diversification. Goldenrods are notorious for their ploidy variation, with roughly 14% and 32% of recognized North American species being polyploid or including multiple cytotypes, respectively. We used traditional chromosome counts and flow cytometry to examine cytogeographic patterns, biogeographic and evolutionary hypotheses, and species boundaries in S. subsect. Humiles. Chromosome numbers and DNA ploidy determinations are reported for 337 individuals, including 148 new reports. Cytotypes show significant geographic structuring. Solidago simplex and S. spathulata were uniformly diploid (2n = 18) in western North America, while cytogeographic patterns in eastern North America were regionally complex and included 2n, 4n, and 6n cytotypes. Cytotypes within S. simplex were ecogeographically segregated and mixed‐ploidy populations were rare. Data from this study and additional biosystematic data indicate that cytotypes in S. simplex fulfill the requirements of multiple species concepts and should best be treated as distinct species. Polyploid cytotypes possibly formed recurrently, however, and evolution and species boundaries within poly ploid S. simplex will require additional study. Results from this study and accumulated data from other studies suggest that biological species diversity in Solidago is considerably higher than currently recognized taxonomically.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147108/1/tax611014-sup-001-PDF.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147108/2/tax611014.pd

The disjunct coastal plain flora in the Great Lakes region

Three areas in the Great Lakes region are known to harbor species whose primary range is the coastal plain: (1) the southeastern Georgian Bay region of Ontario, (2) the sandplains near Lake Michigan in southwestern Michigan and northern Indiana, and (3) the lacustrine sand deposits in central and northern Wisconsin. Secondary areas with smaller concentrations are found in the southeastern Lake Ontario region of New York, the Lake Erie region, small areas of north-central Illinois, and local areas of northern Michigan. These areas are all sand deposits associated with postglacial lakes and drainage channels. A review of the flora of the Great Lakes region disclosed a list of 62 primarily coastal plain species that are disjunct to the Great Lakes region.The species are largely herbs, nearly half are graminoids, and many are annuals. Their habitats are primarily sandy, gravelly, or peaty emergent shores of shallow, soft-water ponds and small lakes with fluctuating water levels, or sometimes sandy, periodically flooded swales. A few species are aquatic, and fewer still are bog or wet forest species. Most are evident only during years of low water levels, and sometimes their appearance is quite sporadic, making survey and monitoring work difficult. However, the consequences of loss of populations can be severe since, with disjuncts, there may be no seed source nearby to facilitate recolonization of sites. The sandy lakeshore habitats are frequently prime recreational lands, thus creating additional pressures.Previous hypotheses for the occurrence of these disjuncts suggested gradual migration along the shores of postglacial lakes and drainages. However, these species do not typically inhabit shores of rivers and large lakes. As well, habitats along these shores undoubtedly were not continuous. Nevertheless, the localized occurrence of the species at the termini of major postglacial drainages in spite of the more widespread availability of apparently suitable habitats argues against random long distance dispersal. Here proposed is that these species migrated into the Great Lakes region through dispersal jumps of varying distances between substantial areas of suitable habitat created along major postglacial drainage channels. Once in the Great Lakes area, they were most successful in areas with extensive drying shorelines.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31904/1/0000857.pd

Utilizing RADseq data for phylogenetic analysis of challenging taxonomic groups: A case study in Carex sect. Racemosae

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141466/1/ajb20337-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141466/2/ajb20337.pd

Burton V. Barnes as a forest botanist

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/120432/1/Dick2016_Barnes_Tribute.pdfDescription of Dick2016_Barnes_Tribute.pdf : Main articl

Allozyme variation and genetic relationships among species in the Carex willdenowii complex (Cyperaceae)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142149/1/ajb20546.pd

Three newly described species of carex sect. fecundae (cyperaceae) from Central America and typification of two related names

Three new species of Carex sect. Fecundae (Cyperaceae) are described from Central America. Carex orothanatica from Costa Rica, Carex siguanabae occurring in El Salvador and Honduras, and Carex via-aquae from Costa Rica and Panama. The three new species are compared with relatives. In addition, two related names, Carex lehmanniana Boott, and C. lehmaniana var. simplex Kük., are lectotypifie

Chromosome Number Changes Associated with Speciation in Sedges: a Phylogenetic Study in Carex section Ovales (Cyperaceae) Using AFLP Data

Phylogenetic analysis of amplified fragment length polymorphisms (AFLP) was used to infer patterns of morphologic and chromosomal evolution in an eastern North American group of sedges (ENA clade I of Carex sect. Ovales). Distance analyses of AFLP data recover a tree that is topologically congruent with previous phylogenetic estimates based on nuclear ribosomal DNA (nrDNA) sequences and provide support for four species groups within ENA clade I. A maximum likelihood method designed for analysis of restriction site data is used to evaluate the strength of support for alternative topologies. While there is little support for the precise placement of the root, the likelihood of topologies in which any of the four clades identified within the ENA clade I is forced to be paraphyletic is much lower than the likelihood of the optimal tree. Chromosome counts for a sampling of species from throughout sect. Ovales are mapped onto the tree, as well as counts for all species in ENA clade I. Parsimony reconstruction of ancestral character states suggest that: (1) Heilborn’s hypothesis that more highly derived species in Carex have higher chromosome counts does not apply within sect. Ovales, (2) the migration to eastern North America involved a decrease in average chromosome count within sect. Ovales, and (3) intermediate chromosome counts are ancestral within ENA clade I. A more precise understanding of chromosomal evolution in Carex should be possible using likelihood analyses that take into account the intraspecific polymorphism and wide range of chromosome counts that characterize the genus

Slender False Brome (Brachypodium sylvaticum, Poaceae), an Invasive Grass New to Ontario, Canada

Brachypodium sylvaticum, Slender False Brome, an invasive Eurasian grass, is reported for the first time in Ontario and eastern Canada from Grey County, southern Ontario. The only previous Canadian record is from Vancouver Island, British Columbia. The species is widespread in the U.S. Pacific Northwest, where it is spreading aggressively throughout much of western Oregon. In the eastern U.S.A., known populations are few and localized, although the species will likely spread

Long-distance dispersal explains the bipolar disjunction in Carex macloviana

PREMISE OF THE STUDY: The sedge Carex macloviana d’Urv presents a bipolar distribution. To clarify the origin of its distribution, we consider the four main hypotheses: long-distance dispersal (either by mountain hopping or by direct dispersal), vicariance, parallel evolution, and human introduction. METHODS: Phylogenetic, phylogeographic, and divergence time estimation analyses were carried out based on two nuclear ribosomal (ETS and ITS) regions, one nuclear single copy gene (CATP), and three plastid DNA regions (rps 16 and 5′ trn K introns, and psb A-trn H spacer), using Bayesian inference, maximum likelihood, and statistical parsimony. Bioclimatic data were used to characterize the climatic niche of C. macloviana. KEY RESULTS: C arex macloviana constitutes a paraphyletic species, dating back to the Pleistocene (0.62 Mya, 95% highest posterior density: 0.29–1.00 Mya). This species displays strong genetic structure between hemispheres, wiThtwo different lineages in the Southern Hemisphere and limited genetic differentiation in Northern Hemisphere populations. Also, populations from the Southern Hemisphere show a narrower climatic niche wiThregards to the Northern Hemisphere populations. CONCLUSIONS: C arex macloviana reached its bipolar distribution by long-distance dispersal, although it was not possible to determine whether it was caused by mountain hopping or by direct dispersal. While there is some support that Carex macloviana might have colonized the Northern Hemisphere by south-to-norThtranshemisphere dispersal during the Pleistocene, unlike the southwards dispersal pattern inferred for other bipolar Carex L. species, we cannot entirely rule out north-to-souThdispersion.Ministerio de Economía y Competitividad CGL2016-77401-