Assessment Notes

Justification

Ramaria coulterae is an uncommon but widespread species in the Pacific Northwest, currently known from ~30 sites. Habitat requirements are largely unknown, but it appears to be restricted to mature or old growth forests, which are in decline in the Pacific Northwest due to stand replacing fires and logging. While the species is likely undergoing a population decline due to the loss and decline of its habitat, its broad distribution could be mitigating the rate of decline. Based on current information, it is assessed as Least Concern.

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Taxonomic notes

Field identification of Ramaria is often very difficult, with macromorphological differences being subtle and often intergrading (especially in older fruitbodies).

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Geographic range

Ramaria coulterae is known from the Sierra Nevada in California, USA, the Cascade Range in California and Oregon, and the Rocky Mountains of Idaho. It has also been reported from Colorado, although the identity of these collections should be confirmed, and are not included in this assessment.

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Population and Trends

The population occurs over a widespread area, mostly on drier (east) side of the Cascade Range in California and Oregon, and the Rocky Mountains in Idaho, with a disjunct subpopulation in the Sierra Nevada. Currently it is known from c.30 sites (Siegel et al. 2019, MyCoPortal 2021). Data to fully assess trends are lacking, but this species was found at six sites during the USFS 2011-2013 southern Cascade fungal surveys; mostly from mature and old growth forests. It is included on the Oregon Natural Heritage rare fungi list (Oregon Biodiversity Information Center 2019) as a S2S3 species. Occurrences of this species may be under-reported in California because of misidentifications and lack of collecting. While the species is likely undergoing a population decline due to ongoing logging and an increase in fire frequency and intensity, its broad distribution could be mitigating the rate of decline.

Population Trend: Decreasing

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Habitat and Ecology

It is ectomycorrhizal with conifers, especially Fir (Abies spp.), Western Hemlock (Tsuga heterophylla) and Douglas-fir (Pseudotsuga menziesii). It is believed to be restricted to mature and old growth forest, although many records do not disclose habitat information. Fruit bodies are solitary or scattered from ground, with fruiting in spring.

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Threats

This is a ectomycorrhizal fungus species dependent on living host trees for viability. The major threat to this species and its co-occurring co-generic taxa is habitat loss, via the logging of old-growth forests to which this species has a preference for and an increase in fire frequency and intensity.

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Conservation Actions

This species is included on the United States Forest Service Northwest Forest Plan Survey and Manage list of rare/old growth forests dependent fungi, and has been actively surveyed for since the late 1990’s (Castellano et al. 2003). It is included on the Oregon Natural Heritage rare fungi list (Oregon Biodiversity Information Center 2019), as a S2S3 species. Logging or machine clearing of understory should be limited in mature (or old growth forest) in areas this species in known to occur.

Modern taxonomic research on Ramaria is needed to resolve taxonomic issues. Field surveys to obtain a better understanding of population trends and habitat requirements of this species, i.e. if it is restricted to mature and old growth forests and its status in the Colorado Rockies, are also needed.

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Use and Trade

This species is edible, but rarely collected by humans.

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Source and Citation

Mueller, G.M. 2025. Ramaria coulterae. The IUCN Red List of Threatened Species 2025: e.T273197328A273247129. Accessed on 20 November 2025.

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• Country occurrence