SAMPLES ARE CURRENTLY UNAVAILABLE. Please contact the NEON Biorepository for information about when these samples will become available. Plant tissue collected from select plant species during plant diversity sampling (NEON sample class: div_geneticarchive_in.geneticSampleID). Plant species diversity is measured once or twice annually in the field. The plot-based method yields plant species data at multiple scales that provide an understanding of changes in composition, distribution, and abundance of native and non-native plant species. A subset of observed plant species is collected and archived. Leaf tissue is also collected and curated for analysis of plant genetic diversity over space and time. Leaf tissue collected in the field is immediately placed in coin envelopes, then into resealable plastic bags filled with desiccant to begin the air-drying process. Once dry, leaf tissue is shipped to the NEON Biorepository where it is archived in its original coin envelope at -80 degrees Celsius. See TOS Protocol and Procedure: Plant Diversity Sampling and TOS Science Design for Plant Diversity (https://data.neonscience.org/documents) for more information about this sample class. NEON datasets (https://data.neonscience.org/home) associated with this sample class include Plant Presence and Percent Cover.