Wiregrass makes pickles?!?
If you look closely at wiregrass spikelets, you may sometimes see green or black things that look like pickles or grossly misshapen seeds. What are they? Pickles? Dead seeds?
These are sori (pronounced sore-eye) of the smut fungus Langdonia walkerae. Sori are the reproductive structures that hold the spores before they are dispersed. Dr. Abeer Alqurashi and colleagues identified this smut fungus (Alqurashi et al. 2021) as a new species and discovered that it infects wiregrass flowers during the flowering period. Then, instead of seeds, you get sori, or, as we call them, “wiregrass pickles.”
We don’t know much at all about the relationship between wiregrass and this smut fungus. For example, there might be other ways the smut fungus affects wiregrass besides decreasing seed output. We also don’t know anything about its life cycle in pine savannas and what makes wiregrass plants more susceptible to infection. Recently, we published the results of a survey of wiregrass populations in North and South Carolina and Georgia (Fill et al. 2024). These populations had been burned at various times of the year before the survey. Fewer plants were infected in locations that had burned during the winter and early spring than in the summer. This might reflect a tradeoff with the low seed output of plants burned in winter and early spring. However, we found that the amount of infection varied a lot among the populations, and there are (unmeasured) conditions specific to each location that probably affected infection levels more.
Have you seen “wiregrass pickles”? We would love to hear your observations!
References
Fill, J.M., Meadows, I., Walker, J.L., Crandall, R.M. and Kerrigan, J.L., 2024. Smut fungus (Langdonia walkerae) incidence is lower in two bunchgrass species (Aristida stricta and A. beyrichiana) after fires early in the year. American Journal of Botany, p.e16286.
Alqurashi, A.S., Kerrigan, J. and Savchenko, K.G., 2021. Morphological and molecular characterization of Langdonia walkerae sp. nov. infecting Aristida stricta and A. beyrichiana in longleaf pine-grassland ecosystems in the southeastern USA. Fungal Systematics and Evolution, 8(1), pp.39-47.
