Kühn) Langdon & Full., (1978), previously known as Sphacelotheca reiliana, and Sporisorium reilianum, is a species of biotrophic fungus in the family Ustilaginaceae.

[3] Symptoms of the fungus are expressed on both the tassels of corn and sorghum as well as on the actual ear in the form of large smut galls.

[5] Sporisorium reilianum is noted to have a sexual stage in its disease cycle similar to that of Ustilago maydis.

These sporidia fuse due to a compatibility or likeness that induces the formation of dikaryotic mycelium, which is infectious and parasitic.

[8] Maize head smut occurs in most maize-growing areas, including many regions of North America, Australia, Asia, and southern Europe.

Conventional methods, including pathogen isolation and microscopic morphological study, are labor-intensive and cumbersome, and sometimes yield inconclusive results.

More recently, in 2012, a method using Fourier transform infrared spectrometry was established for identification of S. reilianum spores.

In comparison with other cereal crops, such as rice (Oryza sativa) and wheat (Triticum aestivum), maize has fewer qualitative resistance genes that have been used extensively by breeders.

[10] The pathogenic tendency of Sporisorium reilianum as illustrated above is to carry out its life cycle in congruence with the growth of either maize or sorghum as the host plant.

The massive crop loss that this pathogen can create is devastating to producers who are unaware of the teliospores overwintering in the soil; which, can survive for many years.

Treatment of seeds with a fungicide during planting or prior to harvest is important to limit the spread of spores especially if high risk field areas known by the producer.

It is important to limit transmission of spores to disease free areas via harvesting equipment or planting tools.