Evaluation location: Iowa, United States
The USDA-ARS North Central Regional Plant Introduction Station (NCRPIS) in Ames, Iowa evaluated a select set of Monarda accessions held within the U.S. National Plant Germplasm System (NPGS) Germplasm Resource Information Network (GRIN) consisting of M. austroappalachiana (1); M. bradburiana (1); M. didyma (1); M. fistulosa (14); M. fistulosa var. menthifolia (1); and M. sp. (1). Seeds were sown on April 21, 2020 and cultivated in the greenhouse until approximately the 5 leaf-pair stage, when they were hardened off and then transplanted by hand on June 16, 2020 to a field at the NCRPIS farm (42.013896°N, -93.661259°W). Seedlings were grouped by accession in 12-plant rows, with 2 rows per accession (inventory lots 20ncaim1 and 20ncaim2). Plants were spaced 25 cm apart within rows and 152 cm apart between rows in a complete randomized block design with two blocks. Observation data was captured between May 20 and August 19, 2021, for the following descriptors: plant habit, inflorescences per stem, plant height, plant width, population variability, stem branches, chlorosis, inflorescence profusion, bract color, first flower date, last flower date, days in bloom, floral quality, seed ripening date, stem surface, petiole length, petiole pubescence, adaxial leaf surface pubescence, abaxial leaf surface pubescence, leaf margin, leaf tip shape, leaf base shape, corolla upper lip shape, leaf length, leaf width, inflorescence diameter, corolla tube length, capitulum diameter, calyx width, calyx length, corolla color, leaf area, leaf length-width ratio, upper corolla lip length, and lower corolla lip length. The values reported are averages of the two replications.