**3. Results and Data Resources**

*Sequence Characteristics and Upload to BOLD and GenBank*

A total of 2722 DNA barcode sequences were generated and uploaded to the BOLD and GenBank reference databases (both publicly available, Supplementary Table S1). Most DNA barcode sequences represented the *rbcL* locus (789), and the fewest sequences were generated for the *matK* locus (597 sequences). Overall, 650 and 686 sequences were generated for ITS2 and *psbA-trnH*, respectively. Among the DNA barcode sequences presented in this data release are 12 families, 292 genera, and 604 species that previously did not have barcode sequence data available in GenBank. All sequences uploaded to BOLD are contained within the BOLD projects GRDTX and GRDMO. All sequences uploaded to GenBank are part of the GGI-Gardens Bio-Projects (ID: PRJNA791936 & PRJNA485943).

These sequences represent important resources for biodiversity studies and will facilitate rapid species identification and ecological studies that seek to understand plant community composition [9] and species interactions [32], as well as conservation assessments that depend upon DNA barcoding to identify and control invasive species, e.g., [33] and enforce policies regarding the trade in endangered plants, e.g., [34,35]. Expanding the plant DNA barcode sequence reference library can also help botanic gardens to accurately identify species in their living collections, i.e., [36]. We hope this work encourages others who work with plant DNA barcodes to contribute to growing DNA barcode reference databases to improve these public resources.

**Supplementary Materials:** The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/d14040234/s1. Table S1. List of samples collected for the Global Genome Initiative for Gardens projects selected for DNA barcoding in this study, with GenBank accession numbers and genomic voucher identification numbers. All the sequences are included in the GGI-Gardens BioProjects PRJNA791936 and PRJNA485943 in GenBank and BOLD projects GRDTX and GRDMO. Each Collector Number includes a link to the digital genomic voucher record stored in the Smithsonian Biorepository.

**Author Contributions:** Conceptualization, M.R.G. and J.S.; methodology, M.R.G., M.M.C. & J.S.; software, A.D.; formal analysis, J.S.; resources, K.B.B. and J.A.C.; data curation, J.S.; writing—original draft preparation, M.R.G.; writing—review and editing, J.S., M.M.C., M.R.G., A.D., K.B.B., J.A.C.; project administration, M.R.G., K.B.B., J.A.C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the Global Genome Initiative under grants GGI-Gardens-2019- 206, GGI-Gardens-2020-246, and GGI-Partnerships-2017-167.

**Institutional Review Board Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available in Supplementary Table S1.

**Acknowledgments:** All laboratory work was conducted in the Laboratories for Analytical Biology (LAB) at the National Museum of Natural History in Washington, DC and at the Museum Support Center in Suitland, MD. Genomic vouchers are deposited in the Smithsonian Institution Biorepository as well as the DNA banks at the Botanical Research Institute of Texas (BRIT) and the Missouri Botanical Garden (MO). Herbarium vouchers for samples associated with Genbank Projects PRJNA791936 and PRJNA485943 have been deposited in the BRIT and MO herbaria, respectively. M.R.G. thanks Faranhoz Khojayori, Seth Hamby, and Jerrod Stone for their assistance with the collection of samples used in this work from BRIT. M.M.C. thanks Danielle Hopkins, Stephanie Keil, Ella Ludwig, and Gabrielle McAuley for their assistance with collections made at the Missouri Botanical Garden. The sequences published as part of thisfFigur work were supported by the Global Genome Initiative, with assistance from Jose Zúñiga. Any paper(s) resulting directly from this specimen-processing project should reference support from the Global Genome Initiative and the Laboratories of Analytical Biology, National Museum of Natural History, Smithsonian Institution.

**Conflicts of Interest:** The authors declare no conflict of interest.
