Multispecies invasions raise questions about the mechanisms enabling coexistence. Differences in regenerative niche requirements may reduce competition and facilitate coinvasion in related species with similar life forms, phenology, and habitat ranges. We expected closely related woody invaders to differ in germination phenology and seedling stress tolerance during early life stages.

Understanding the genomic basis of diversification is a central goal in evolutionary biology. In recent years, the development and use of pangenomes, a genomic representation of multiple individuals within a lineage (a set of related populations, subspecies, ecotypes, or species), has enabled researchers to differentiate between DNA sequences shared by all individuals of a given lineage (core regions) from those present only in some individuals (accessory or variable regions). Differentiating between core and accessory regions has highlighted a key limitation of relying on a single reference genome: It captures the genetic code of only one individual and this biases genomic analyses and our understanding of diversification. Here, we propose that by identifying genes associated with both core and accessory regions, we can deepen our understanding of the processes underlying diversification. We suggest that analyzing pangenomes and accessory regions will provide deeper insights into diversification, hybridization, and the genetic basis of adaptation and speciation.

What maintains trait divergence in the face of gene flow? Two varieties of wild snapdragon (Antirrhinum majus) characterized by divergent flower color hybridize in their native range. Selection on flower color genes is indicated by sharp clines, but the selective agents have not been demonstrated. Although previous work has focused on pollinators, pigmentation genes can also contribute to abiotic stress tolerance. We hypothesized that pigmentation in A. majus mediates stress tolerance, which could contribute to hybrid zone maintenance through parental niche divergence or hybrid maladaptation. Specifically, we tested whether morphotype mediates drought tolerance in an experiment comparing magenta-flowered var. pseudomajus, yellow-flowered var. striatum, and their pink-flowered hybrid cross.

The mustard genus Boechera (Brassicaceae) is notorious for rampant intra- and interclade hybridization, which has produced a complex reticulate network of apomictic diploid, triploid, and tetraploid hybrids. A recent hypothesis suggested the possibility of intergeneric hybridization between Boechera and other closely related genera. Here we explored the origin of Boechera tiehmii, a putative hybrid between Boechera and Nevada.

Pollinator-mediated plant-plant interactions may be negative (i.e., competition, reproductive interference) or positive (i.e., facilitation). Especially when co-flowering with close relatives (e.g., congeners), negative interactions through reproductive interference may be strong and result in floral trait divergence and increased pollination niche partitioning. However, when pollination services are limited, positive effects of pollinator sharing through floral trait similarity may outweigh the costs of reproductive interference. We therefore tested for evidence of negative or positive pollinator-mediated plant-plant interactions across a gradient of varying congeneric co-flowering contexts in the genus Rhexia (Melastomataceae).

Colorful traits in biology are often shaped by the perception biases of animals making choices based on color. In angiosperms, flower color diversity may reflect selection by pollinators with distinct visual systems, leading to divergence within or between species. Yet, how these visual biases influence continuous flower color variation-particularly in natural hybrid swarms-remains poorly understood.

Polyploid research has traditionally distinguished between autopolyploids and allopolyploids on the basis of evolutionary origins, modes of inheritance, or chromosomal pairing behavior during meiosis. It has long been recognized, however, that a binary classification does not accurately reflect the complexity and diversity inherent to polyploid organisms, and that these definitions may be inadequate to capture biological diversity. Moreover, inferred conditions at polyploid formation are often obscured by numerous post-polyploidy genomic processes, necessitating a temporal perspective on the meaning of polyploid terminology. In this review, we explore the concept of the "polyploid continuum" and highlight the temporal biological fluidity between the classically recognized alternative end points of autopolyploidy and allopolyploidy. We consider aspects of the polyploid continuum that might meaningfully be evaluated on the basis of genetic variation, including at the sequence, structural, and functional levels. We discuss the utility of the polyploid continuum concept and how it might be visualized as a multidimensional landscape of polyploid diversity that represents a temporal snapshot at any one time. This perspective may better reveal the genesis of polyploid diversity in its many dimensions and provide a framework for understanding the dynamic evolutionary processes that underpin polyploid variation.

The proper classification of taxa is often debated, particularly when organisms lack qualitative diagnostic traits. Highbush cranberry taxa (Viburnum spp.) have been the subject of such disputes since their characterization by 18th- and 19th-century botanists. Despite their allopatric distributions-V. trilobum in North America, V. opulus in Europe, and V. sargentii in Asia-these taxa have received numerous taxonomic treatments as species, subspecies, and varieties due to their morphological similarities. Genetic evidence has shown these taxa to be distinct; however, the human-mediated introduction of V. opulus and V. sargentii into North America may remove their geographic and genetic isolation, with implications for the conservation of V. trilobum.

The Glossopteridales are an extinct group of seed plants that dominated mid to high latitude floras of the supercontinent Gondwana during the Permian (298-251 million years ago). Reconstructing their functional ecology is thus of particular importance for understanding the forests of that time period. Previous studies have shown evidence for diverse strategies favoring individual persistence and regeneration in glosssopterids. This evidence includes the production of epicormic and basal shoots, but there is no evidence of root suckering (i.e., new shoots from the root system).

Flower morphology influences the architecture of plant-pollinator interaction networks. Flowers with deep corolla tubes and bilateral symmetry have a narrower pollinator range, hence are considered more specialized than shallow radial flowers. Past interspecific comparisons revealed positive correlations between flower depth and nectar production rates in a few plant communities, suggesting that specialized flowers may allocate more resources into food rewards for pollinators.

Diverse mechanisms of reproductive isolation can limit gene flow between species. The Orchidaceae, one of the most species-rich and morphologically diverse plant families, often exhibits strong pollinator-mediated isolation due to highly specialized pollination systems. Autonomous self-pollination is also common in orchids and contributes to both speciation and the maintenance of reproductive barriers among closely related taxa. Although agamospermy (clonal seed production without fertilization) occurs in several orchid species, its role in reproductive isolation remains unclear.

Ecological niche differentiation of spore germination and sporophyte habitat promote the coexistence of fern species in the cloud forest, but the role of the gametophyte is unknown. Because fern sporophytes only establish where the inconspicuous gametophytes grow and reproduce, the environmental tolerance of the gametophyte has been hypothesized to be associated with the light preference of the sporophyte.

Fire is a key ecological process that shapes ecosystems globally, yet fire adaptation strategies remain unclear for many species, especially for ground lichens that are reliant on pyrogenic landscapes but are evidently fire-intolerant. In the pyrogenic Florida scrub, fire-sensitive Cladonia ground lichen species are an important component of the ground layer and influence ecosystem processes. The endangered Cladonia perforata is of special concern because fire regimes can dictate the persistence of the species. We aim to clarify (1) its subpopulation trends, (2) its post-fire recovery, and (3) the influence of microhabitat factors on these patterns.

Why did it take so long for angiosperms to diversify after they arose? Here I consider the indirect but potentially crucial impact of the "photosynthetic revolution" on plant-herbivore coevolution. Increased vein density in fossil leaves implies a doubling in photosynthesis 125-100 million years ago. Higher photosynthetic rates increase the opportunity cost of anti-herbivore defenses, favoring shifts to chemically diverse, low-cost, low-molecular-weight qualitative toxins (e.g., alkaloids) from chemically stereotyped, high-cost, high-molecular-weight quantitative toxins (e.g., tannins). Given the greater functional significance of incremental changes in defensive compounds of lower molecular weight, shifts to qualitative toxins should accelerate plant-herbivore coevolution and species diversification. The large genome and cell sizes of ferns and gymnosperms should drive lower rates of coevolutionary diversification by decreasing vein density and photosynthetic rates; high vein density found in many euasterids, eurosids, and monocots should drive higher diversification rates. This theory might also explain the general restriction of qualitative toxins to herbaceous plants, given the higher photosynthetic rates of herbs vs. woody plants. Lower hydraulic limitation and selection for small genomes in short, fast-growing, short-lived plants should foster evolution of small cells, fine vein networks, high leaf N levels and photosynthetic rates, reliance on qualitative toxins, and high speciation rates.

Comparative surveys allow us to characterize the influence of specific factors on population genetic diversity and structure. We conducted a comparative phylogeographic study for three Mexican oak species to identify how their climatic niche preferences and breadth may have influenced historical demography and range shifts during Pleistocene climatic oscillations.

Pollination by beetles is relatively rare in orchids, and this has been attributed to the clumsy behavior of beetles being unsuitable for the precise pollen transfer mechanisms that characterize the orchid family. We investigated floral specialization for beetle pollination in the rare fire-dependent South African orchid Disa elegans and explored its implications for the efficiency and spatial pattern of pollen dispersal.

We aimed to elucidate the spatiotemporal origins and biogeographic history of Polynesian blueberries within Vaccinium sect. Myrtillus, specifically those endemic to Hawai'i and the closely related V. cereum in southeastern Polynesia.

The structural and dynamic properties of columnar cacti are key inputs for stability analyses; however, no previous studies have been able to resolve these properties from full-scale tests in situ.

Reconstructing the evolution of crop plants is fundamental to understanding their origins, ecological adaptations, and impacts on ecosystem processes. However, our understanding of crop evolution stems largely from archaeology and genetics, with less focus on a trait-based ecological approach. Crop-specific studies have shown that phenotypic traits changed substantially during domestication and modern breeding. Yet, global comparative analyses across multiple species and traits remain scarce. Moreover, we largely ignore which plant traits distinguish wild species that were domesticated (progenitors) from those that were not, and how their ecological profiles differ. Here, I propose a conceptual model that integrates crops, their wild progenitors, and other non-domesticated herbaceous species into Grime's CSR theory and the integrated framework of plant form and function. This model provides insights into the evolutionary trajectories of domesticated plants along economics, root-microbial collaboration, and size spectra, shedding light on the ecological strategies of the wild progenitors of crops. After a comprehensive review, I emphasize that crops and their wild progenitors share similar resource-use traits, as progenitors were already highly acquisitive species. Conversely, main trait differences between domesticated and progenitor plants occur along size and collaboration axes, driven primarily by selection of large-seeded genotypes and intensive agricultural practices, respectively. I propose that crops deviate from the disturbance-adapted strategies of their wild progenitors toward more competitive ones, including links to different stages of evolution under cultivation. Finally, I outline implications for future breeding programs and the origins of agriculture, and recommend research directions to further advance our understanding of crop evolution.