Amur honeysuckle (Lonicera maackii) is an important invasive plant species in the Ohio River Valley. Previous work has shown extensive dieback of honeysuckle in the region, coupled with the appearance of the native fungal pathogen, honeysuckle leaf blight (Insolibasidium deformans). Our goal was to find if the blight causes growth decline or mortality in Amur honeysuckle. Seedlings were grown under greenhouse conditions in 2017. Treated seedlings were sprayed with a spore solution prepared from blighted leaves that were collected from the field. They were placed into a growth chamber with conditions set for optimum spore growth and then returned to the greenhouse after leaf blight began to develop. Growth (height, total stem length, leaf area, and leaf number) and dark-adapted chlorophyll fluorescence (F_v/F_m) were measured periodically over the growing season. A repeated-measures analysis of aboveground growth indicated that larger, faster-growing plants were more likely to be infected, but their growth rates were subsequently reduced much more than uninfected treated plants and controls. There were positive correlations between F_v/F_m and RGR (relative growth rate). Blighted leaves had lower values of F_v/F_m than uninfected leaves. No infected plants died, but this experiment supports our hypothesis that leaf blight causes a significant growth decline in Amur honeysuckle. Future work will determine if the patterns seen under greenhouse conditions hold in the field.

Despite their important ecosystem services, most wetlands in Kentucky and the surrounding region have been lost. Many restoration attempts have occurred, but the success of seeding or planting, which is often done after restoration, is unclear. To our knowledge, seeding success relative to other propagule inputs has never been quantified. We measured the restoration success of a four-year-old emergent open-canopy wetland, with seven adjacent ponds near the banks of the Ohio River in Kentucky. Potential restoration plant origins include (a) from the seedbank and surrounding area, (b) a native seed mix designed for upland and wetland restorations, and (c) from the onsite prerestoration wetland. We tested the hypotheses that elevation and distance from an established wetland pond are driving factors to establish species that dominate the wetland vegetative cover. Plant cover and relative elevation were determined in 78 1-m² plots. Although most species (73%) came either from seedbank or offsite sources, the remainder appear to have come from seeding (14–16%) and the prerestoration wetland (11–14%), and the latter two sources accounted for almost 50% of the total cover at the site. Ordination supported the hypotheses that distance from the prerestoration pond and relative elevation were the two most important factors determining patterns of plant cover. Despite its modest contribution to plant diversity, the prerestoration pond had an important effect on plant patterns. While the site falls into Kentucky Wetland Rapid Assessment (KY-WRAM) Category 1 (most disturbed), prevalence index (PI) scores, which are based on species wetland classifications, appear to be similar to or higher than those of other created wetlands in the United States.

Bottomland forests provide ecosystem services, such as nutrient exchange and pollution entrapment, and generally improve aquatic and riparian habitats. In West Virginia, little is known about the development and resiliency of isolated bottomland sites dominated by Quercus L. species, which have declined in area primarily from human impacts (e.g., draining and development). In this study, we used vegetation surveys and tree-ring analysis to investigate successional dynamics and the timing and drivers of recent overstory mortality in a remnant stand located on the floodplain of the Meadow River. Our results indicate a rapid change in vegetation cover at the site between 2011 and 2017, with a significant decrease in tree canopy cover and an increase in light-demanding, flood-tolerant, herbaceous species cover. Historical trends in tree establishment indicate an absence of Quercus palustris Münchh. recruitment after the 1960s and an increase in the recruitment of Acer rubrum L. and other shade-tolerant species. Furthermore, temporal trends in hydroclimate-tree growth relationships suggest that an increasingly temperate climate and higher water table benefited A. rubrum at the expense of Q. palustris beginning in the 1990s. Taken together, these findings suggest a gradual, multidecade process of plant community reorganization beginning in the mid-20th century. This process might have continued unabated, but flooding and persistent high water in 2003 amplified the wetting trend and initiated the progression of widespread overstory mortality. Our results suggest that Q. palustris forests in the Meadow River wetlands are maintained by infrequent stand-replacing disturbances (i.e., prolonged inundation), but the current long-term wetting trend could create site conditions unfavorable to tree growth. Furthermore, these findings highlight the need for additional analysis of bottomland vegetation dynamics in the Appalachian Mountains, where increased hydroclimate variability, including extreme flooding, is predicted.

Hand-pollination experiments followed by epifluorescence microscopy of pistils of Uvularia grandiflora Smith (Colchicaceae) indicated a trend toward late-acting self-incompatibility. Pollen tube growth in pistil tissue of bagged but unmanipulated flowers (mechanical self-pollination) was insignificant. As each pistil produces three stigmatic lobes, insects deposited pollen on an average of more than two in open-pollinated flowers. Medium-sized male and female bees were dominant pollen vectors representing four genera (Andrena, Lasioglossum, Nomada, and Osmia) within four families (Andrenidae, Halictidae, Apidae, and Megachilidae). Male bees comprised greater than half (59%) of the bees collected. Pollen load analysis indicates that the majority of female bees collected on U. grandiflora carried the pollen grains of the host flower's pollen mixed with grains of one or more coblooming species (polylectic foraging). The majority of nectar-drinking male bees also carried pollen loads that included grains of at least one coblooming species. We recorded pollen morphotypes of 12 coblooming vernal species on bees carrying mixed loads. Gynes of Bombus species were infrequent visitors. We report the rediscovery of females of Andrena uvulariae and the first collection of males of A. uvulariae from U. grandiflora.

The understanding of the species traits of Acer L. growing in subtropical and tropical America is relevant because this region represents its most southern geographic range in the hemisphere. This study evaluates the morphological variation and updates the taxonomic status, distribution, and phylogenetic relationships of Acer in Middle America. A total of eight taxa are recognized. The presence of Acer negundo subsp. mexicanum is documented for Honduras, while five taxa are restricted to northern Mexico (Acer negundo var. arizonicum, A. negundo var. texanum, Acer glabrum var. neomexicanum, Acer grandidentatum, Acer grandidentatum var. sinuosum), whereas Acer binzayedii is endemic to western Mexico. Only Acer skutchii and A. negundo subsp. mexicanum are widely distributed in the investigated area. The populations are often fragmented and disjunct. The phylogenetic analysis identifies the A. grandidentatum populations from northwestern Mexico as a separate lineage. Descriptions, distribution maps, photographs, and conservation assessments of the species as well as a key to species are provided.

Aquatic vegetation was surveyed at Mammoth Spring, AR, representing the first extensive survey of this resource since 1859. Thirty-eight angiosperm species were identified during this study, including 17 species of monocots and 21 species of eudicots. Seven species were nonnative, but they are not considered invasive. Eleven of the species reported from the spring in 1859 are still present, but some previously reported taxa were not found and other taxa are reported for the first time. Species no longer found at the spring may be due to misidentifications in the earlier study or extirpations due to climate change, anthropogenic disturbances, or unknown factors. The diversity of aquatic plants in Mammoth Spring is similar to that reported from other regional large springs and a few species are shared in common among these springs.

This work details the spontaneous vascular plant flora of New York City's Central Park for the period 2013 to 2017. We divided the 341-ha (843-acre) park into 36 zones and used a modified timed-meander sampling method to collect herbarium specimens and silica-dried samples (for DNA analysis) of spontaneous, naturalized plants. We collected each new species until we ceased to find any species that had not been previously encountered in any zone. We collected 1,468 specimens, representing 438 species and two subspecific taxa from 262 genera and 89 families, and a number of cultivated species not analyzed is this work. We find that 45% of the flora are native (198 species) and 54% (240 species) are nonnative. Three species are of unknown native status (<1%). The largest families are Poaceae (56 species), Asteraceae (55), Rosaceae (27), Fabaceae (20), and Polygonaceae (17). The largest genera are Persicaria (8 species), Carex (7), Acer (7), Cyperus (6), Rubus (6), and Eragrostis (6). Seven species are ranked as rare, threatened, or endangered by New York Natural Heritage Program. Thirty-six species are listed as prohibited or regulated invasive species by New York State. Four species new for New York State were collected in Central Park during this study. We documented 76 additional species since the last inventory of 2007. The percentage of native species has increased by 5% since 2007. The data suggest that management efforts focused on controlling invasive species and planting and supporting native species have been effective. The spontaneous, naturalized flora is listed in Appendix I. Spontaneous plants that appear once or sporadically but do not persist without repeated introduction are listed as waifs in Appendix II. The species are listed with scientific and common name, native status in New York State, coefficient of conservatism, New York Natural Heritage Program rarity ranking (S1–S5), observed frequency in Central Park (rare, infrequent, and frequent), and observed species fecundity for Central Park (decreasing, stable, or increasing). All species reported are vouchered by herbarium specimens and silica-dried tissue samples at the New York Botanical Garden.

This work details the spontaneous vascular plant flora of New York City's Central Park for the period 2013 to 2017. We divided the 341-ha (843-acre) park into 36 zones and used a modified timed-meander sampling method to collect herbarium specimens and silica-dried samples (for DNA analysis) of spontaneous, naturalized plants. We collected each new species until we ceased to find any species that had not been previously encountered in any zone. We collected 1,468 specimens, representing 438 species and two subspecific taxa from 262 genera and 89 families, and a number of cultivated species not analyzed is this work. We find that 45% of the flora are native (198 species) and 54% (240 species) are nonnative. Three species are of unknown native status (<1%). The largest families are Poaceae (56 species), Asteraceae (55), Rosaceae (27), Fabaceae (20), and Polygonaceae (17). The largest genera are Persicaria (8 species), Carex (7), Acer (7), Cyperus (6), Rubus (6), and Eragrostis (6). Seven species are ranked as rare, threatened, or endangered by New York Natural Heritage Program. Thirty-six species are listed as prohibited or regulated invasive species by New York State. Four species new for New York State were collected in Central Park during this study. We documented 76 additional species since the last inventory of 2007. The percentage of native species has increased by 5% since 2007. The data suggest that management efforts focused on controlling invasive species and planting and supporting native species have been effective. The spontaneous, naturalized flora is listed in Appendix I. Spontaneous plants that appear once or sporadically but do not persist without repeated introduction are listed as waifs in Appendix II. The species are listed with scientific and common name, native status in New York State, coefficient of conservatism, New York Natural Heritage Program rarity ranking (S1–S5), observed frequency in Central Park (rare, infrequent, and frequent), and observed species fecundity for Central Park (decreasing, stable, or increasing). All species reported are vouchered by herbarium specimens and silica-dried tissue samples at the New York Botanical Garden.