Dutch Elm Disease - Ophiostoma

Vascular Wilts

Dutch Elm Disease - Ophiostoma

DED culture

A culture of Ophiostoma growing on agar in a petri dish. A few pieces of elm wood are also on the plate.


Sporothrix stage. Conidiophores producing conidia. 


Synnemata on elm bark as viewed with a hand lens.


Another view of elm wood with synnemata. Conidia collect on the top of each synnema in a sticky droplet.

top of a synnema

Microscopic view of the top of a synnema showing a flair of conidiophores that would produce the conidia.


Another view of the top of the synemma showing many conidiophores producing very small conidia. The conidia accumulate in a sticly droplet on the synemma.

DED perithecia

A and B strains coming together will result in perithecia forming on the elm wood.


Perithecia have a bulbous base and long neck. Ascospores accumulate on the tip in a sticky matrix.


A perithecium as seen through the microscope with the spore mass oozing out.