• Proposed
  • 2Under Assessment
  • 3Preliminary Assessed
  • 4Assessed
  • 5Published

Pachycudonia spathulata (S. Imai) S. Imai

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Scientific name
Pachycudonia spathulata
(S. Imai) S. Imai
Common names
IUCN Specialist Group
Cup-fungi, Truffles and Allies
Incertae sedis
Assessment status
Proposed by
Noah Siegel
Comments etc.
Noah Siegel

Assessment Notes

Taxonomic notes

Described as Cudonia spathulata based on a 1931 collection made in Big Basin State Park in Santa Cruz County, California, USA (Imai 1942), and later transferred into the genus Pachycudonia (Imai 1950). Also placed in the genus Spathularia (Mains 1956).

Genetic studies (Ge et al. 2014) suggest that Pachycudonia can be considered a synonym of Cudonia. No genetic analysis has been done on Pachycudonia spathulata, but based on micro features, there is no evidence to suggest it doesn’t belong in Cudonia.

Why suggested for a Global Red List Assessment?

Pachycudonia spathulata is a small fungus with an irregularly rounded, convoluted to somewhat spatulate, bright golden yellow to orange ‘head’, a pale orange stipe that becomes brownish from the base upwards in age, and leathery, non-gelatinous flesh. Most reports are from winter and early spring from under manzanita (Arctostaphylos spp.).

It remains a poorly known species, but was recently included in “A Field Guide to the Rare Fungi of California’s National Forests” (Siegel et al. 2019) and “FunDiS Rare 10 Challenge” (Fungal Diversity 2020).

Based on habitat and current reports, this species in likely far more common than records indicate. Therefore I recommend listing as Least Concern.

Geographic range

Southern Oregon through the Sierra Nevada foothills, and eastern slopes of the coast range and around the northern portion of the Central Valley of California, south to Santa Cruz, County, California. Likely under reported and more widespread than currently known.

Population and Trends

Populations remain poorly documented, however as this species has become better known, more populations have been reported. The scarcity of reports probably had more to do with the fact it was never published in any field guides, and was only known in obscure scientific literature.

Based on the habitat it is now known to occur in, this species in likely a lot more common than reported, and stable.

Population Trend: Stable

Habitat and Ecology

Scattered to gregarious in duff under manzanita (Arctostaphylos spp.) and Pacific Madrone (Arbutus menziesii) in the Coast Ranges and Sierra Nevada Foothills. Nutritional mode not known. Fruiting in winter and early spring.

Temperate Forest


No specific threats have been identified with regards to this species.

Conservation Actions

No specific conservation actions has been identified with regards to this species at this time.

Research needed

Surveys for this species in suitable habitat. Population and trends.

Use and Trade

None known.


Fungal Diversity. 2020. Rare 10 Challenge. https://fundis.org/protect/take-action

Ge, Z.W., Yang, Z.L., Pfister, D.H., Carbone, M., Bau, T. et al. 2014. Multigene Molecular Phylogeny and Biogeographic Diversification of the Earth Tongue Fungi in the Genera Cudonia and Spathularia (Rhytismatales, Ascomycota). PLOS ONE 9(8): e103457. https://doi.org/10.1371/journal.pone.0103457

Imai, S. 1942. Contributiones ad studia monographica Geoglossacearum. Botanical Magazine Tokyo 56:523–527.

Imai, S. 1950. On the genus of Cudonia constrictospora S. Ito et Imai. Botanical Magazine Tokyo 63(749): 234–235.

Siegel, N., Vellinga, E.C., Schwarz, C., Castellano, M.A. and Ikeda, D. 2019. A Field Guide to the Rare Fungi of California’s National Forests. Bookmobile: Minneapolis, MN. 313 p.

Country occurrence

Regional Population and Trends

Country Trend Redlisted