fluted bird's nest or splash cups (less common name)

Description:

This fungus resembles a miniature bird's nest with numerous tiny "eggs"; the eggs, or peridioles, are actually lens-shaped bodies that contain spores. C. striatus can be distinguished from most other bird's nest fungi by its hairy exterior and grooved (striated) inner walls. Although most frequently found growing on dead wood in open forests, it also grows on wood chip mulch in urban areas. The fruiting bodies are encountered from summer until early winter. The color and size of this species can vary somewhat, but they are typically less than a centimeter wide and tall, and grey or brown in color. Another common name given to C. striatus, splash cups, alludes to the method of spore dispersal: the sides of the cup are angled such that falling drops of water can dislodge the peridioles and eject them from the cup. The specific epithet is derived from the Latin stria, meaning "with fine ridges or grooves

Habitat:

Cyathus striatus is a saprobic fungus, deriving its nutrition from decaying organic material, and is typically found growing in clusters on small twigs or other woody debris. It is also common on mulch under shrubs. The features of the microenvironment largely influence the appearance of C. striatus; all else being equal, it is more likely to be found in moist, shallow depressions than elevated areas.It is very widespread in temperate areas throughout the world, growing in summer and fall.

Notes:

The cone shaped fruiting body of Cyathus striatus makes use of a splash-cup mechanism to help disperse the spores. When a raindrop hits the interior of the cup with the optimal angle and velocity, the downward force of the water ejects the peridioles into the air. The force of ejection rips open the funiculus, releasing the tightly wound funicular cord. The hapteron attached to the end of the funiculus is adhesive, and when it contacts a nearby plant stem or stick, the hapteron sticks to it; the funicular cord wraps around the stem or stick powered by the force of the still-moving peridiole (similar to a tetherball). The peridioles degrade over time to eventually release the spores within, or they may be eaten by herbivorous animals and redeposited after passing through the digestive tract