Q: I have sent you pictures of something I found this morning on our cedar mulch in back of our house. I have never seen this before and would like to know what it is – and if we need to try to kill it. It is in the back of our house on the East side, but gets little sun because of a large oak tree. It is also to the side of a “Macho fern.” It appears to be perfectly formed little cups with seeds of some sort in it. These little “cups” are between 1/8″ and 1/4″ in diameter. Thank you for any information you can give me on this growth.
A: The photos were wonderful and made the identification very easy. The small structures are birds nest fungi. These odd and fascinating little fungi look like tiny birds’ nests with small eggs. Bird’s nest fungi belong to a group called saprophytes that live on decaying material. They are in fact part of the “full circle of life” – those who eat and those who are eaten. The fruiting bodies form little cuplike nests which contain spore-filled structures that resemble eggs. The nests are called “peridia” and serve as splash cups; when raindrops strike the nest, the eggs (called “periodoles”) are projected into the air, and they latch onto twigs, branches, and leaves waiting for the perfect weather conditions to develop into new birds nest fungi. They do little harm to the environment so no chemical treatment is necessary. If you wish to get rid of them, collect them into trash bags and toss them.