You can find these *everywhere*. This picture of the bird's nest fungus, Crucibulum laeve, is from the Rutgers Ecological Preserve, but I have seen them amongst the mulched hedges on Main Street in Highland Park and even growing in the outdoor potted plants in downtown Philadelphia.

You have to look closely, however. These fungi are hardly one centimeter across and tend to grow in fairly dense clusters of tens to hundreds of individual bird's nests. I like this particular picture because you get to see the fungus going through the stages of opening from right to left. The right-most fungus is a barrel with a thin membrane across the top. As the top expands, the membrane splits open, revealing a 'nest' filled with little white 'eggs'. These eggs are called peridioles, and they contain thousands of spores. When it rains, the water splashes inside of the cup, ejecting the peridioles up to several feet away from the nest, allowing the fungus to spread.

I've also noticed the less common Cyathus stercoreus, which has black eggs, growing on mulch piles along 4th Ave in Highland Park. Keep an eye out for both of these right after a rainfall in mulch piles near the sidewalk — or if you're in the woods, growing on twigs amongst the leaf litter.

Photo: Vikas Nanda