Pygmaeomyces thomasii E. Walsh & N. Zhang, sp. nov. FIG. 7B, E–J
MycoBank number: MB 832253; Index Fungorum number: IF 832253; Facesoffungi number: FoF;
Typification: USA. NEW JERSEY: West Pygmy Pine Plains, Little Egg Harbor, 39.708783, −74.372567, 26 m alt, from roots of apparently healthy Pinus rigida and Kalmia latifolia in a pygmy pine forest, 22 Jun 2016, E. Walsh & N. Zhang PP16K26 (holotype RUTPP- PP16K26). Ex-type culture (CBS146528). GenBank: ITS = MN017028; RPB2 = MN486053.
Etymology: The epithet honors the first author’s late father, Thomas A. Walsh, who encouraged her in her scientific and research endeavors.
Description: Colonies on MEA 26 mm diam on aver- age with standard deviation (SD) of 5.3 mm after 7 d in the light at 25 C, Fawn Color, mycelium with a Cinnamon margin, sparse aerial hyphae light brown, reverse pigmented, Cinnamon. Colonies on MEA 24 mm diam on average with SD of 2 after 7 d in the dark at 25 C, and 17.3 mm diam on average with SD of 2.51 after 7 d in the dark at 30 C. Colonies on WA 7 mm diam on average with SD of 0 after 7 d in the dark at 25 C, Wood Brown, aerial hyphae sparse, reverse pigmented, Avellaneous. Colonies on WA 6.7 mm diam on average with SD of 0.6 after 7 d in the dark at 25 C, and 7 mm diam on average with SD of 0 after 7 d in the dark at 30 C. Coenocytic hyaline hyphae becoming septate to form subglobose to globose vesicles. No sporangia were observed. Microchlamydospores hyaline, globose to subglobose, 6–15 × 4–8 μm (n = 100, mean 10 × 6 μm, SE 1.5 μm, 1 μm). Zygospores not observed. Other material examined: USA. NEW JERSEY: Same location as ex-type culture, from roots of apparently healthy Pinus rigida and Kalmia latifolia in the pygmy pine plains, 22 Jun 2016, E. Walsh & N. Zhang PP16K33A, PP16K77A, and PP16P25.
Figure 7. Cultures on MEA+LA 60-mm plates. A. Pygmaeomyces pinuum. B. Pygmaeomyces thomasii. C–I. Microchlamydospores. C–D. From Pygmaeomyces pinuum ex-type culture. E–I. From Pygmaeomyces thomasii ex-type culture. J. Switchgrass seedling roots inoculated with Pygmaeomyces thomasii ex-type culture. Bars = 10 μm.