Assessment Notes

Justification

Craterellus calicornucopioides is widespread and common. Local declines are expected, mostly from habitat loss due to Sudden Oak Death killing the preferred host tree, Tanaok, but the overall population is thought to be broadly stable. Due to the the total extent of occurrence and limited local declines, it is assessed as Least Concern.

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Taxonomic notes

Craterellus calicornucopioides was long referred to by the name of the European species, C. cornucopioides (Thiers 1985, Arora 1986). The distinct western North American entity was described from a type collection made in Mendocino County, California, USA (Frank 2015).

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Geographic range

Craterellus calicornucopioides is known from central California, USA, north into Washington state. This species is most common in Tanoak (Notholithocarpus densiflorus) dominated forests in northern California and south-west Oregon, but occasional in live oak woodlands to the south and found mostly with Oregon White Oak (Quercus garryana) to the north.

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Population and Trends

The population of this species is widespread, occurring over a large expanse of the western USA. Locally, it is a very abundant species. Most of the population is currently stable, but decline of Tanoak due to the introduced pathogen Sudden Oak Death (Phytophthora ramorum) is a localized threat.

Population Trend: Stable

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Habitat and Ecology

Craterellus calicornucopioides is ectomycorrhizal with hardwoods, especially Tanoak (Notholithocarpus densiflorus), Coast Live Oak (Quercus agrifolia) and Oregon White Oak (Q. garryana). It has also been reported with Vaccinium and/or Douglas fir (Pseudotsuga menziesii) in the northern portion of its range (Frank 2015). It is very common in the mixed evergreen forests of northern California, occasional elsewhere, fruiting from early winter into spring.

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Threats

Overall, this species' population appears stable, with local subpopulations under threat due to the introduced pathogen Sudden Oak Death (Phytophthora ramorum) killing large swaths of Tanoak.

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Conservation Actions

There is a need to limit the spread of Sudden Oak Death in northern California forests. No specific research is needed with regards to this species.

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Use and Trade

Craterellus calicornucopioides is a highly desired edible species, and is collected by hobbyist foragers and commercial pickers. However, no decline has been recorded due to current harvest practices.

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Source and Citation

Siegel, N. 2021. Craterellus calicornucopioides. The IUCN Red List of Threatened Species 2021: e.T189958461A198625182. Accessed on 24 November 2025.

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• Country occurrence