Sporisorium cruentum

On panicles of Sorghum halepense, with sori in the spikelets replacing the seeds, causing atrophy; these blackish sori exhibit a very fragile peridium, containing inside a spore mass (teliospores), which upon release with the aid of wind end up dispersing, leaving only a columella in the centre.

Little to highlight in the microscopy, only globose to subglobose sterile cells, hyaline, slightly thick-walled, solitary, forming small clusters or in chains, 12 to 17 µm long and 10 to 15 µm wide.

Spores spherical to ovoid, smooth-walled to very slightly verruculose, dark greenish-brown under the microscope, 6 to 9 µm long, 5.5 to 8.5 µm wide, and with abundant granular content inside.

A species very similar to its congener, Sporisorium sorghi, on the same substrate, the latter having a thinner soral peridium and smaller spores.