Abstract
Variation of the sporidesmin content of samples of spores of Pithomyces chartarum (Berk. & Curt.) M. B. Ellis collected from pasture is reported. The proportion of sporidesmin readily extracted from these spores by water varies widely, although high extraction is possible with large volumes of water. The instability of sporidesmin in aqueous solutions exposed to sunlight is demonstrated. The possible role of exposure to rain and sunlight in reducing the sporidesmin content of pasture spores is discussed.