2.1 Sample Collection.
Samples of maize and wild grasses with characteristic stromata ofPhyllachora spp . (Figure 1 A-F)) were collected from across North America and Mexico in 2018 and 2019 (Table 1). Field specimens of infested maize and other grasses were collected by numerous individuals from the agricultural community as described in Kleczewski et al (2020). Samples were pressed, dried at room temperature, and stored at 20°C in manilla envelopes until processed. Herbarium specimens were obtained from the U.S. National Fungus Collection (BPI, Beltsville, Maryland) and the University of Illinois Herbarium (Urbana, Illinois), which included specimens on maize and other grasses from additional hosts, countries, and years (Table 1). A total of 186 samples from 16 hosts, and 15 countries collected from 1905-2019 were included in the analyses.