Dissingia crassitunicata

Species Fungorum (2025) transfers Helvella crassitunicata to Dissingia crassitunicata; these represent the same concept for the element.

This cup-fungus is characteristic of montane forests in the higher portions of the Cascades of Oregon and Washington; it also occurs in the Olympic Mountains and in British Columbia and Alaska. Thus it is truly a western species. Only in one place, Mt. Rainier National Park, does it seem to be abundant. It is seldom common enough for one to see many fruitings on an afternoon walk and it fruits irregularly; however, careful searching may reveal more sites. The species needs to be watched and more of the sites conserved.

This species has been documented so far from Alaska, British Columbia east into the Canadian Rockies, the Olympic Mountains in Washington, and the Oregon and Washington Cascades. Possibly present in the Colorado Rockies but specimens await study to confirm the identification.

Twenty-two locations are in the ISMS summary of locations, the list of collections has about 27 entries for this species. Abbott and Currah (1997) list 5 sites from British Columbia, 1 from Alaska, and 6 from Washington including those cited by Weber (1975).

This species is probably mycorrhizal so any event that results in reduced vigor of the photosynthetic partner or its removal is likely to stress the fungus as well; I've not see it in severely disturbed sites, but it is often found along hiking paths. Once the forest is gone or severely damaged, decades probably elapse before the habitat will again be right for this species.