The Collared Earthstar Mushroom that is found in the Pacific Northwest is most often found in coniferous forests, but sometimes you will see them in maple and alder groves.
If you cut through a young fruit body, you will see that the interior is white, but it gradually turns into a dark brown powdery mass as the spores mature. Spores are emitted from the apical hole as the wind blows across it, much larger puffs of spores escape when raindrops hit and compress the spore sac. Collared Earthstars are larger than other Earthstar species, and they have a spore sac diameter of up to 6 cm and arms that can reach 15 cm when fully outstretched. A sac forms in the center, a hole on the top of the sac deploys spores when the wind blows across it or raindrops fall upon it.
When fully expanded the rays of these mushrooms more than double their diameter. The number of star rays is very variable with 5 to 8 being the most common. Earthstars are generally found under coniferous trees, often on sloping rather than flat ground.
They fruit after rain in late summer and autumn but can be found all year round.