Drechslera/Bipolaris-type conidia

Drechslera/Bipolaris-type conidia are similar in several asexual ascomycetes genera including Drechslera, Bipolaris, Helminthosporium, and Exserohilum. These fungi are either plant pathogens or saprobes in the natural environment, and their conidia are airborne. They are known to be allergenic and can also cause fungal sinusitis. Because these genera have similar conidia, they are usually identified as Drechslera/Bipolaris-type spores in air sample analysis.

The spores are usually cylindrical with a single attachment scar at the base. There is a great variation in conidial size based on the diversity of species in this group from about 15 µm to more than 100 µm in length. In most species the conidia appear pseudoseptate suggesting the septa (crosswalls) are not complete.