Pyrenophora seminiperda is a minor plant pathogen that causes leaf spots on many grasses.

[1] It is an important generalist grass seed pathogen[2] which causes visible cylindrical masses of black fungal hyphae (stromata) to grow from infected seeds.

Hence the common name "black fingers of death"[3] It has been hypothesized that the fungus arrived in North America with invasive grasses from Eurasia.

[3][5] Various secondary metabolites of the fungus, including Cytochalasin B, Pyrenophoric Acid-B, and Spirostaphylotrichin W, appears to be responsible for the seed killing.

[6][7][8] Dr. Erin Mordecai discusses BFOD and Cheatgrass during a seminar at the Department of Ecology and Evolutionary Biology at University of Michigan, Feb. 16, 2017