2026 REU Mentors and Projects
Here is a list of REU mentors and potential projects that are available for 2026. On your application, please request three mentors and projects. Assignment of accepted students to mentors will be based upon student requests, mentor input, and any special qualifications needed for individual projects.
Using Next-Generation Sequencing to Resolve Taxonomic Confusion in Malagasy Casearia (Salicaceae s.l.) (mentor Wendy Applequist). Casearia is a complicated genus; especially in sect. Casearia, the flowers are tiny and offer few useful characters. The last competent treatment in Madagascar, in 1946, recognized five species, but the actual number is much higher. Previous REU students have described individual species or raised varieties to species level using largely vegetative characters (Applequist & Gates 2020, Philpott & Applequist 2023, Wang & al. 2023; McWaine & Applequist, MS in prep.), leaving a core complex of species of eastern humid forests with moderate-sized variable leaves that are difficult to resolve by morphological taxonomy. DNA will be extracted from specimens from MBG’s herbarium and Angiosperms-353 Illumina sequencing will be performed to produce a nuclear-DNA phylogeny of the Malagasy species and identify monophyletic groups.
Resolving the Identity of the North American Endemic Moss Cylindrothecium floridanum Duby (Entodontaceae) (mentor John J. Atwood). Recent research has uncovered numerous rare, poorly known North American bryophytes with unresolved taxonomy. The moss Cylindrothecium floridanum Duby (≡ Entodon floridanus (Duby) A. Jaeger), is one of these. Described from a single Florida specimen in 1875, it was originally compared to the common and widespread E. seductrix (Hedw.) Müll. Hal., though some morphological characters are not consistent with that species. Cylindrothecium floridanum was later considered dubious by late 19th century bryologists, but the type specimen was never re-examined. The name has since been overlooked or forgotten, and is not included in modern floristic literature. The student will study the morphology of the type specimen and compare it with five North American, Mexican-Andean and Caribbean Entodon species using specimens in the MBG bryophyte herbarium. The student will gain experience in microscopy, plant dissection, working with bryophyte specimens, and using a camera lucida to prepare figures, as well as an understanding of bryophyte morphology, biogeographic distribution patterns, and taxonomy. The project is expected to clarify the identity of C. floridanum and result in a short publication.
Using genomic data to optimize ex situ collections of imperiled plants( mentor Christy Edwards). Ex situ species conservation is the maintenance of populations of species outside their native habitat in intensively managed living collections. For plants, botanical gardens (broadly defined to include arboreta, seed banks, etc.) are the institutions principally in charge of ex situ conservation programs. The role of ex situ conservation is to safeguard against extinction, sheltering a representative sample of a species’ genetic diversity from the threats experienced by wild populations, and to provide plant material for reintroductions, population augmentations, restoration, and related practices. Therefore, an important concern for staff tasked with managing living collections for ex situ conservation is the extent to which these collections represent the intraspecific variation present in a species. In this project, the student will investigate patterns of genetic diversity and structure in an ex situ collection at the Missouri Botanical Garden. This project will involve analyzing whole-genome resequencing data generated from individuals in our living collection to understand how genetic diversity is structured within and among source populations and to identify loci showing signatures of local adaptation of environmental variation. The study will then use the information to help improve the efficiency of our living collection while maintaining as much genetic variation as possible. Available study species include Quercus arkansana and Dalea foliosa.
Using Micro-Traits to Disentangle the Taxonomy of Bulbophyllum (Orchidaceae) in Madagascar (mentor Gunter A. Fischer). Bulbophyllum is a pan-tropical genus with over 3000 species with several diversification centers, Madagascar being one of them with over 300 species. Several sections within the genus in Madagascar are insufficiently known and morphological studies are urgently needed. This project will focus on a group of 15 species described in section Trichopus. All species are extremely small with flowers often not being larger than a few millimeters. Flower dissections will be conducted using state of the art microscopy to document micro-morphology of floral details relevant for species delineations. The student will gain experience in microscopy, flower dissection, anatomical drawings, digital imaging and processing and learn about orchid taxonomy.
Post-Invasion Soil Legacy Effects on Herbaceous Species Performance During Forest Restoration (mentor Andrew Kaul). Invasive shrubs can leave a significantly altered soil legacy in terms of chemical, physical, and biotic properties, which inhibit germination or growth of other species. During forest restoration, after removal of invasive shrubs, a common management technique is to re-introduce desirable native herbaceous species. Most of these fail to establish from seed, and success has proven difficult to predict. One mechanism explaining this variation may be sensitivity to soil legacy effects. Identifying the phylogenetic and functional trait signals of higher tolerance to invasive legacy effects will help to identify candidate species for use in future ecosystem restoration efforts. This project will test the tolerance of 20 common native and non-native herbaceous species in Eastern US broadleaf forests to bush honeysuckle (Lonicera maackii) soil legacy effects. We will collect soil samples in an area heavily invaded by honeysuckle, and a representative area at the same site without honeysuckle. Half of each sample will be sterilized to isolate abiotic vs. biotic soil effects. We will monitor the germination (growth chambers) and growth rates (greenhouse) of each species in each of the four soil treatments over six weeks. We will measure soil physical and chemical variables and characterize the soil microbial community. Analyses will highlight (1) the nature of an invasive shrub’s effect on important soil variables, and (2) how variation in herbaceous species’ tolerance to these changes is related to plant growth strategies characterized by functional traits.
Diversity in Latin American Tree Nurseries (mentor Laura Toro, with Leland Werden and Rebecca Cole). This project examines how tree nursery (vivero) production may be inadvertently homogenizing restored tropical forests. While large-scale reforestation initiatives across Latin America are planting native species, many programs rely on a narrow subset of species that are economically viable and easy to grow—often nitrogen-fixers and fast-growing trees—while overlooking harder-to-propagate species with large or recalcitrant seeds. For example, Mexico's Sembrando Vida program has planted millions of seedlings on the Yucatán Peninsula, but nurseries in the region produce predominantly Swietenia and Tabebuia, limiting what practitioners can actually plant. This pattern mirrors conventional agriculture and raises concerns about functional narrowing of restored ecosystems, reduced biodiversity, and limited capacity for natural forest recovery over time. The project will compile and analyze data on species produced by large production nurseries (both private and government) to understand what trees are actually available for restoration practitioners and identify gaps in functional diversity. Students will play a critical role in the project by participating in:
- Cleaning species lists from Latin American tree nurseries in an existing extensive database.
- Merging functional trait data from global databases (e.g., seed size, dispersal syndrome, wood density) to characterize nursery portfolios.
- Comparing functional trait distributions of nursery species to those found in natural reference forests.
- Analyzing patterns and producing figures to visualize functional gaps in nursery production.
Students will receive comprehensive training in ecological data analysis and functional trait approaches. Basic knowledge in Excel is required; experience with R or Python for data analysis is preferred. Students will be co-advised by Laura Toro (Mobot), Leland Werden (ETH Zürich), and Rebecca Cole (University of Alaska, Organization for Tropical Studies) and will engage in a collaborative international research network.
Evaluating Key Biodiversity Areas in the Tropical Andes: Plant Data, Bias, and Conservation Priorities (mentor J. Sebastian Tello). Key Biodiversity Areas (KBAs) are a central tool in global conservation planning, but their effectiveness for plant conservation depends on how botanical data are distributed, and used. This project addresses several unresolved challenges in KBA-based conservation, using a global hotspot of plant diversity—the Tropical Andes—as a case study. Biodiversity data are well-known to be spatially biased, reflecting history and accessibility to data collection rather than underlying biological patterns. While this problem is well known, its influence on the definition of KBAs remains poorly understood. This project will test whether Andean KBAs, particularly those triggered by plants, are disproportionately located in well-sampled areas as indicated by herbarium and iNaturalist record density. Additionally, KBAs are often treated as static despite rapidly changing threats across their landscapes. The project will evaluate how plant-triggered KBAs are threatened by deforestation, cropland expansion, mining and oil concessions, development of road infrastructure, and climate change. This analysis will provide important insight into how KBAs bridge biological importance and conservation urgency. Using spatial analyses in R, the student will integrate KBA data with plant occurrence records and environmental / threat datasets. This project will produce a diagnostic assessment of how plant data and dynamic threats shape conservation priorities in the Tropical Andes via Key Biodiversity Areas.