Coprinellus truncorum

These mushrooms appeared in a large pot that contains a Dampiera. The first photo shows fairly young specimens, with veil remnants still present as very obvious granules on the caps. The granules are easily washed or brushed off and in the second photo, taken a day later, you see older caps in which the granules are not as obvious – and the caps are paler. In the third photo you see a cap fragment, placed so as to show the gills. Immature spores are colourless but become black at maturity. The spores do not all mature at the same time. Where the gills are white the spores are immature, where the gills are black the spores are mature and where the gills are light brown to dark brown the spores are at various intermediate stages of development.

I’ve said before that today’s cameras can capture surprisingly fine detail. The final photo shows a much closer view of the cap fragment. Here you see numerous microscopic organs, called cystidia, protruding from the gills. This, and the other photos, were taken with the macro lens that sits almost permanently on my camera. This photo doesn’t show the fine details of the cystidia (for that a microscope is needed), but it tells you that cystidia are present. If you go back to the third photo you might see (perhaps after enlarging it) that the upper gill has faint speckles on it. Those are the cystidia. They are colourless and so don’t show where the spores are still immature but do show where the spores have matured.

One of the photos in this sighting (Coprinellus truncorum (Coprinellus truncorum)) shows a microscope view of a stained cross-section of several gills in which a few cystidia are visible. The cystidia in this species are large and protrude well above the level at which the spores are produced. Hence, a mass of mature spores gives a nice, black backdrop – which is why the cystidia are easy to see in those parts of a gill where the spores are mature. In much the same way as colourless, glass beads (scattered over a black carpet) show clearly when a bright light is shone on them.