Long, browned area of infection which is a coalescing of several infected leaf spots

Long, browned area of infection with small, black spore-producing bodies ("pycnidia")

Browned area of infection with small, black spore-producing bodies ("pycnidia")

Dark-field observation of infected leaf tissue with many spore-producing bodies ("pycnidia") and a measurement scale

Dark-field observation of infected leaf tissue with several spore-producing bodies ("pycnidia") and a measurement scale

Dark-field observation of infected leaf tissue with one spore-producing body ("pycnidium") and a measurement scale

Asexual spores of the fungus Septoria tritici with a measurement scale

Asexual spores of the fungus Septoria tritici with a measurement scale and measurement of some individual spores