Premise of research. Stylosanthes, comprising approximately 50 species, is considered a taxonomically difficult genus, as its component taxa demonstrate very uniform external morphological characteristics. The presence of very similar species complexes within the genus is one of the principal factors complicating the identification of its taxa. Within that context, the present study seeks to morphologically

Premise of research. Rapid environmental changes have raised questions about the capacity of plant populations to adapt to novel conditions. Salinity is increasing in both urban and rural areas because of irrigation and road deicing salt. While adaptation to salinity is found in some plant species, salt impairs plant fitness for the vast majority. Breeding to enhance adaptation to salinity has proved

Premise of research. Fossil fruits and seeds of Zingiberales provide essential data on the past diversity and distribution of the order, augmenting our understanding of the evolutionary history of gingers, bananas, and relatives.Methodology. Three different types of zingiberalean fruits and seeds from the Late Cretaceous–early Cenozoic Deccan Intertrappean beds of central India were studied using physical

Premise of research. Breeding systems dictate the potential for self-fertilization in plants and may therefore have a strong influence on evolutionary and ecological processes. Previous investigations of breeding systems in Ericaceae indicate variation in self-sterility, but studies from the megadiverse genus Erica are almost entirely lacking. Here we quantify the degree of self-sterility and autofertility

Premise of research. We present here the first reports of vivipary in Neotropical Melastomataceae and remark on the evolutionary relationships among the three lineages that share this feature.Methodology. The observational data were gathered during field expeditions and from herbaria collections. These data were then plotted onto a phylogeny developed for the Melastomataceae in a previous study.Pivotal

Premise of research. A trade-off between seed mass and seed output defines a central axis of ecological variation among plant species. While an observed negative seed mass–seed output relationship is hypothesized to reflect universal constraints on resource allocation in all plants, domestication has likely altered this relationship.Methodology. I use a data set of seed mass and seed output (measured

International Journal of Plant Sciences, Volume 182, Issue 1, January 2021.

International Journal of Plant Sciences, Volume 182, Issue 1, January 2021.

Premise of research. Metrosideros polymorpha is a landscape-dominant tree species endemic to the Hawaiian Islands. Although the group is famous for its ecological amplitude and variation in vegetative characters, little attention has been paid to variation in its “shaving brush” flowers, which occur in inflorescences of diverse sizes and colors. We aimed to determine whether the floral variation observed

Premise of research. Floral synorganization is a structural feature of many speciose angiosperm taxa and is considered a morphological innovation paving the way for evolutionary diversification. Staphisagria is sister to the remaining Delphinieae, the only lineage of Ranunculaceae characterized by zygomorphic flowers. We aim at providing a description of floral organogenesis and morphogenesis in both

Premise of research. Early Cretaceous flowers recovered from Portugal and North America are some of the oldest and most informative angiosperm structures known. Analyses of this material provide a more direct basis for inferring floral structure and biology in early angiosperms than extrapolations based solely on extant taxa, and they have documented an unanticipated diversity of angiosperms, including

Premise of research. A two-phase fern spike occurred immediately after the Cretaceous-Paleogene (K/Pg) mass extinction event. Solely on the basis of palynological evidence, researchers have traditionally attributed the first phase of this spike to the proliferation of a single species of a Cyathea-like fern in the earliest Danian. This traditional perspective is challenged by recent investigations

Premise of research. Serotiny is a specialized dispersal mechanism in which seeds are retained on the parent plant and released following a disturbance event. This strategy has evolved repeatedly in plants inhabiting fire-prone regions and typically requires adaptations for the protection and release of seeds. We explore the relationship between serotiny and reproductive morphology in the Cupressaceae

Premise of research. MYB transcription factors are one of the largest families of genes in land plants. They are involved in many regulatory processes, such as primary and secondary metabolism, cell fate and identity, developmental processes, and responses to biotic and abiotic stresses. Phylogenetic studies have mainly focused on R2R3-MYB evolution in seed plants; however, a comprehensive sampling

Premise of research. Bat-pollinated flowers have wide morphologies and produce copious and diluted nectar that commonly spills from flowers. Considering that sugar concentration modulates rheological properties in aqueous solutions, we estimated its role in regulating nectar retention.Methodology. We took three bat-pollinated species with open floral morphologies (Calliandra aeschynomenoides; Hymenaea

International Journal of Plant Sciences, Volume 181, Issue 9, November/December 2020.

International Journal of Plant Sciences, Volume 181, Issue 9, November/December 2020.

Premise of research. In Caryophyllaceae with a gynoecium isomerous with the other floral whorls, carpels can be in either antesepalous or antepetalous position. Morphologists have long been unable to find a unifying hypothesis to explain the different carpel positions in Caryophyllaceae, as variation in carpel position breaks with Hofmeister’s rule of alternating whorls.Methodology. In this study,

International Journal of Plant Sciences, Volume 181, Issue 8, October 2020.

International Journal of Plant Sciences, Volume 181, Issue 8, October 2020.

Premise of research. Prominently winged fruits occur in many families of angiosperms today, but they are rare and poorly documented in the mid-Cretaceous. Tricalycites Newberry ex Hollick is a widely distributed winged disseminule from the mid-Cretaceous to Upper Cretaceous sediments of the United States. However, some of the specimens previously attributed to this genus are morphologically distinct

Premise of research. Vascular plants depend on sexual recombination for generating new genetic variability to meet environmental needs. Nevertheless, members of the early-divergent fern genus Botrychium (Ophioglossaceae) typically maintain gametophytic selfing and show strong inbreeding within populations. To explain this evolutionary anomaly, the existence of previous or current but undiscovered outcrossing

Premise of research. Epiphytic bromeliads endure intense seasonal environmental changes in the canopy of dry tropical deciduous forests. The analysis of the physiological responses of these epiphytes to environmental changes can be useful in assessing their plasticity, vulnerability, and adaptations to such extreme habitats.Methodology. We measured microenvironmental variables and water relations for

Premise of research. Seed conifer cones and their fossil record have been the subject of intensive study over the past century. In those studies, however, the interpretation of fossil cones differs substantially. Additionally, despite the rich fossil record, the last common ancestor of modern conifers remains enigmatic. In this study, we endeavor to reconstruct the original and ancestral character

Premise of research. The Puddledock mesofossil flora from Virginia is the richest source for studying structurally preserved plant fossils in the Early Cretaceous Potomac Group sequence. Together with other mesofossil floras from the Potomac Group and also from Portugal, it is key for direct assessment of the structure, relationships, and reproductive biology of early angiosperms. In this study, a

Premise of research. Urbanization is associated with the fragmentation of natural habitats, a reduction in agricultural pesticides, and high numbers of introduced species. Urbanization has also been connected to declines in native biodiversity, including of important ecosystem service providers such as pollinators. We expected that reported patterns of lower pollinator diversity and abundance in highly

Premise of research. Previous pollination ecology studies of Salvia have shown that there is low specialization for certain subgroups of bees and that pollinator number varies with species and locality. We studied 12 Salvia species (three clades with different corolla morphologies and staminal lever mechanisms) that in part co-occur and coflower to examine prezygotic isolation mechanisms and the degree

Premise of research. In plants, evolutionary shifts from one pollinator guild to another are normally associated with coordinated changes of several floral characters. These might be floral morphology, color, and scent. On the basis of the animals’ different sizes and shapes as well as their visual and olfactory sensitivities or preferences, floral visitors exert different selective pressures on flowers

International Journal of Plant Sciences, Ahead of Print.

Premise of research. Along the western coast of South America, the Peruvian and the Atacama Deserts extend over a length of 3500 km. For a short period in the year, the desert is affected by a dense fog formed under the influence of the Humboldt Current that gives rise to an ephemeral plant community called the “Lomas.” Salvia rhombifolia Ruiz & Pavon is an endemic annual component of the Lomas. Previous

Premise of research. Salvia is one of the most species-rich genera in the world. Its outstanding diversity and subcosmopolitan distribution have prevented the preparation of a modern comprehensive monograph and reevaluation of its classification. As phylogenetic efforts advance to untangle the evolutionary relationships of Salvia, the need for a solid taxonomic footing is increasingly imperative. Accordingly

Premise of research. Salvia grandifolia is a narrowly endemic species known only from the Hengduan Mountains of southwestern China. Previous studies have shown that East Asian Salvia species form a clade, Salvia subg. Glutinaria, and suggested that S. grandifolia, on the basis of geographical distribution, should be included within Glutinaria. Calyx and staminal features, however, indicate that S.

International Journal of Plant Sciences, Volume 181, Issue 7, September 2020.

International Journal of Plant Sciences, Volume 181, Issue 7, September 2020.

Premise of research. Previous studies based on plastid fragments and/or nuclear ribosomal DNA have had limited success resolving relationships within the genus Salvia. This study evaluates the efficacy of complete plastome sequences for phylogenetic inference within Salvia, using the recently established Salvia subg. Glutinaria as a case study. We use these plastomes to identify hypervariable and simple

International Journal of Plant Sciences, Ahead of Print.

Premise of research. Small populations on small islands are intrinsically more vulnerable to population decline and extinction. Nevertheless, small native populations that occur on multiple islands may have life-history characteristics that buffer impacts from novel disturbance regimes, and, rather than contracting, populations may be expanding. We monitored three populations of the orchid Brassavola

Premise of research. Shared ancestry and convergent/parallel evolution are the two primary causes of morphologically similar species occurring in similar climatic niches. Alpine habitats harbor a unique biodiversity that is often characterized by many convergences in life-forms, such as cushion and rosulate habits. Three species of Lomatium (L. greenmanii, L. erythrocarpum, and L. oreganum) are high-alpine

Premise of research. Although the term “pseudobulb” has been used in the literature on Orchidaceae for almost two centuries, no definition establishes unambiguous criteria to distinguish such a succulent shoot from a “normal” stem. It is currently impossible to decide whether variation is continuous rather than categorical.Methodology. We studied three morphological characteristics (succulence index

Premise of research. The morphology of leaves is shaped by both historical and current selection acting on constrained developmental systems. For this reason, the phylogenetic signal of these characters is usually overlooked.Methodology. We investigate morphology of the leaflets of all genera of the Zamiaceae using multiple microscopical techniques to test whether leaf characters present a phylogenetic

Premise of research. The monotypic Lowiaceae remains the least-known family in the plant order Zingiberales, yet it may hold an important key to unraveling the phylogenetic placement of the families Musaceae, Heliconiaceae, Strelitziaceae, and Lowiaceae. After nine phylogenetic studies, the (Lowiaceae, Strelitziaceae) clade is the only stable clade that has emerged in this half of the order. This study

Premise of research. Analyses of the evolution of floral morphology and symmetry broaden our understanding of the drivers of angiosperm diversification. Integrated within a flower, labile floral characters produce different phenotypes that promote variable interactions with pollinators. Thus, investigation of floral evolution may help with inferring potential historic transitions in pollinator modes

Premise of research. Fossil fruit and seed floras are valuable because of the wealth of taxonomic characters that they can provide, but they are rare in the Cenozoic of North America. Here, we document a fossil fruit and seed flora from the Paleocene Denver Formation of the Denver Basin, Littleton, Colorado, representing the first account of an early Paleocene carpoflora in North America. This locality

Premise of research. Climbing plants are important components of modern-day tropical forests and primarily comprise angiosperms, but in Paleozoic tropical forests, pteridosperms were the dominant climbers. Climbing pteridosperms are well known from the Paleozoic floras of Euramerica, while much less is known about climbing pteridosperms from other phytogeographic regions. We document from the earliest

Premise of research. The early Eocene Laguna del Hunco (LH) fossil site, northwestern Chubut Province, Argentina, holds one of the best-preserved and most diverse paleofloras worldwide. The paleoflora comprises ferns, gymnosperms, and flowering plants. Despite the rapidly growing knowledge of its macrofossil record, little is known about the site’s palynological content. Herein, we present the first

Premise of research. Road verges are important refugia for plants, particularly rare or threatened species, in transformed landscapes. However, traffic disturbance could disrupt plant-pollinator interactions and so undermine the conservation value of road verges. Here we investigate the indirect road impact on the pollination and fecundity of a highly threatened shrub, Cyclopia pubescens, through changes

Premise of research. Branching in cycads has received little attention, in part because of a lack of available materials for developmental study. Morphology and mature anatomy have enabled some conclusions to be made, but more observations, which are the basis for the present study, are needed.Methodology. Observations concerning external morphology were made in habitat. Some plants were sectioned

In this conclusion to the volumes celebrating the contributions of Gar W. Rothwell, students reflect on his influence on their intellectual development; an interdisciplinary coauthor on working with him; and colleagues on his contributions to paleobotany, morphology, and the broader plant phylogenetic and scientific world.

International Journal of Plant Sciences, Volume 181, Issue 6, July/August 2020.

International Journal of Plant Sciences, Volume 181, Issue 6, July/August 2020.