A) Herbarium material from a healthy inflorescence of Rhynchospora alba. B) Detail of Rhynchospora alba inflorescence showing spiklets infected with Ustanciosporium gigantosporum. C) Teliospores of Ustanciosporium gigantosporum packed to small cylindrical groups. D) Single teliospores of Ustanciosporium gigantosporum showing thick cell wall. Images by Dominik Begerow.

Ustanciosporium gigantosporum is a plant parasite of Rhynchospora alba growing typically in peat bogs. Based on phylogeny, it is placed within the Anthracoideaceae and mirrors host evolution within the Cyperaceae, as well as part of the Ustilaginales (Begerow et al. 2014). The spores are especially large, giving rise to the current species name (Vanky 2012). Additionally, Kellner et al. (2011) demonstrated that all three mating types of Ustilaginomycotina are present within this species.

References:

Begerow D, Schäfer AM, Kellner R, Yurkov A, Kemler M, Oberwinkler F, Bauer R (2014) Ustilaginomycotina in: The Mycota Vol. VII, 2nd ed.: Systematics and Evolution Part A, ed. by D.J. McLaughlin and J.W. Spatafora 295-329

Kellner R, Vollmeister E, Feldbrügge M, Begerow D (2011) Interspecific sex in grass smuts and the genetic diversity of their pheromone-receptor system. PLoS Genet 7:e1002436. doi:10.1371/journal.pgen.1002436

Vanky K (2012) Smut Fungi of the World. APS Press, St. Paul Minnesota