SAMPLES ARE CURRENTLY UNAVAILABLE. Please contact the NEON Biorepository for information about when these samples will become available. Plant voucher collected from select species during plant diversity sampling (NEON sample class: div_voucher_in.voucherSampleID.pla). 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. These vouchers are housed at NEON facilities for reference and archived in the NEON Biorepository's herbarium. See TOS Protocol and Procedure: Plant Diversity Sampling, TOS Science Design for Plant Diversity, and Standard Operating Procedure: Plant Pressing, Mounting, and Labeling (Herbarium Techniques) (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.