Dolipore septum

Dolipore septa are specialized dividing walls between cells (septa) found in almost all species of fungi in the phylum Basidiomycota. Unlike usual septa, they have a barrel-shaped swelling around their central pore, which is about 0.1-0.2 µm wide. This structure is typically capped at either end by specialized membranes, called "parenthesomes" (after their parenthesis-like appearance under a microscope) or simply "pore caps".