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Concerns about spreading non-native invasive plant species have increased in recent decades following their harmful impacts on ecosystems. Their encroachment, aided by survival and reproductive advantages, can negatively impact ecosystems and biodiversity. These effects often lead to larger long-term issues and can be difficult and expensive to manage. Lonicera maackii (Rupr.) Herder and L. japonica Thunb. are invasive honeysuckle species that can outcompete, inhibit, and reduce the populations of native species, thus threatening biodiversity in invaded regions. Both species have formed naturalized populations throughout much of the eastern United States, including Oklahoma. Both species reproduce quickly, grow prolifically, face less environmental resistance, and tolerate a wider range of environmental conditions than most native plant species. This study, based on field surveys and herbarium records, presents new information on the distribution of L. maackii and L. japonica in eastern Oklahoma. Surveys were conducted in parks and public recreation areas of all 47 counties of eastern Oklahoma. By combining herbarium data and field surveys, we found that L. maackii occurs in fewer counties than expected and L. japonica is present in nearly all counties surveyed. The results also revealed a strong positive relationship between the presence of L. maackii and the population size of towns. We also found a weak and non-significant relationship between the occurrence of L. maackii and the number of non-native species in a county. 

PremiseApocynaceae is the 10th largest flowering plant family and a focus for study of plant–insect interactions, especially as mediated by secondary metabolites. However, it has few genomic resources relative to its size. Target capture sequencing is a powerful approach for genome reduction that facilitates studies requiring data from the nuclear genome in non‐model taxa, such as Apocynaceae. MethodsTranscriptomes were used to design probes for targeted sequencing of putatively single‐copy nuclear genes across Apocynaceae. The sequences obtained were used to assess the success of the probe design, the intrageneric and intraspecific variation in the targeted genes, and the utility of the genes for inferring phylogeny. ResultsFrom 853 candidate nuclear genes, 835 were consistently recovered in single copy and were variable enough for phylogenomics. The inferred gene trees were useful for coalescent‐based species tree analysis, which showed all subfamilies of Apocynaceae as monophyletic, while also resolving relationships among species within the genusApocynum. Intraspecific comparison ofElytropus chilensisindividuals revealed numerous single‐nucleotide polymorphisms with potential for use in population‐level studies. DiscussionCommunity use of this Hyb‐Seq probe set will facilitate and promote progress in the study of Apocynaceae across scales from population genomics to phylogenomics. 

Abstract The fundamental tradeoff between carbon gain and water loss has long been predicted as an evolutionary driver of plant strategies across environments. Nonetheless, challenges in measuring carbon gain and water loss in ways that integrate over leaf lifetime have limited our understanding of the variation in and mechanistic bases of this tradeoff. Furthermore, the microevolution of plant traits within species versus the macroevolution of strategies among closely related species may not be the same, and accordingly, the latter must be addressed using comparative phylogenetic analyses.Here we introduce the concept of ‘integrated metabolic strategy’ (IMS) to describe the ratio between carbon isotope composition (δ¹³C) and oxygen isotope composition above source water (Δ¹⁸O) of leaf cellulose. IMS is a measure of leaf‐level conditions that integrate several mechanisms contributing to carbon gain (δ¹³C) and water loss (Δ¹⁸O) over leaf lifespan, with larger values reflecting higher metabolic efficiency and hence less of a tradeoff. We tested how IMS evolves among closely related yet ecologically diverse milkweed species, and subsequently addressed phenotypic plasticity in response to water availability in species with divergent IMS.Integrated metabolic strategy varied strongly among 20Asclepiasspecies when grown under controlled conditions, and phylogenetic analyses demonstrate species‐specific tradeoffs between carbon gain and water loss. Larger IMS values were associated with species from dry habitats, with larger carboxylation capacity, smaller stomatal conductance and smaller leaves; smaller IMS was associated with wet habitats, smaller carboxylation capacity, larger stomatal conductance and larger leaves. The evolution of IMS was dominated by changes in species’ demand for carbon (δ¹³C) more so than water conservation (Δ¹⁸O). Although some individual physiological traits showed phylogenetic signal, IMS did not.In response to experimental decreases in soil moisture, three species maintained similar IMS across levels of water availability because of proportional increases inδ¹³C and Δ¹⁸O (or little change in either), while one species increased IMS due to disproportional changes inδ¹³C relative to Δ¹⁸O.Synthesis.IMS is a broadly applicable mechanistic tool; IMS variation among and within species may shed light on unresolved questions relating to the evolution and ecology of plant ecophysiological strategies.