• Proposed
  • Under Assessment
  • Preliminary Assessed
  • Assessed
  • LCPublished

Hydnellum cyanopodium K.A. Harrison

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Scientific name
Hydnellum cyanopodium
K.A. Harrison
Common names
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
IUCN Red List Category
Proposed by
Noah Siegel
Noah Siegel
Anders Dahlberg

Assessment Notes

The estimated total number of localities is estimated to be less than 70; with small populations of 1-10 individuals each. Hence the total number of mature individuals is estimated to be less 10 000.

The projected habitat decline, with an estimated 20-25% over the southern half of it’s range over the next 50 years, due to the loss of habitat to urban development and the stress and loss of Sitka Spruce due to fog loss and climate change.

Therefore the species is classified as Near Threatened (A3c)

Taxonomic notes

Harrison (1964) described this species from a A. H. Smith collection made in 1937 from Crescent City, California. All suitable habitat from this area has been since lost; due to logging, farmland development and urban sprawl.

Easily recognized by it’s bluish to bluish purple color of the sporocarps, bluish flesh interior flesh, reddish droplets on the margin when young, and presumptive mycorrhizal association Sitka Spruce.

It could be mistaken for Hydnellum caeruleum, H, regium, or H. peckii.

Hydnellum caeruleum differs by it’s sky blue to brown velvety cap, whitish, blue to brown spines, and most distinctly by it’s orange flesh in the stem and zoned, bluish and orange flesh in the cap.

Hydnellum regium has a darker, bluish black to black cap, darker spines, more fleshy texture to the sporocarp, and has pale to orangish flesh in the stem, transitioning to gray or black cap flesh. It is more common in more northern portions of the Sitka Spruce range, and with Engelmann Spruce (Picea engelmannii) in the Cascade and Rocky Mountain rages. 

It superficially resembles Hydnellum peckii when young, and covered with red exude; the brown colors and strongly acrid taste easily distinguish this species. 

Why suggested for a Global Red List Assessment?

The hydnoid fungus Hydnellum cyanopodium is a conspicous and rare fungus seemingly restricted to mature and old growth forests of the southern portion of Sitka Spruce (Picea sitchensis) range in Western USA. Easily recognized by it’s bluish to bluish purple color of the sporocarps, bluish flesh interior flesh and droplets on the margin when young, and mycorrhizal association Sitka Spruce.  The long lasting, and distinctive sporocarps along with the bluish color leads us to think if this species was more common, it would get noticed. However, despite having a near continuous annual fruitings, long lasting sporocarps and considerable mycological activities during the last decades, it is currently (2016) only known from seven locations on the coast of Carlifornia and Oregon. It is common in two small spruce groves in California, but elsewere rare. 

Geographic range

Hydnellum cyanopodium is known from the central Humboldt County coast in California to Clatsop County on the northern Oregon coast; a stretch of 650 km. All known sites in the southern half of the range are within 1 km of the coast, a couple of the northern sites are slightly more inland (following the distribution of Sitka Spruce), but are still within 3 km of the coast.

There are two unconfirmed sightings (bad photos posted on social media) from Haines, Alaska that may represent this species; however, despite a number of surveys in coastal British Columbia, Canada and southeast Alaska, no records exist from these efforts.

Population and Trends

Only known from 7 sites on the Oregon and Californian coast, (plus two unconfirmed sightings in Haines, Alaska). Locally common in two small spruce groves on the Humboldt County, California coast (most of the Mushroom Observer observations come from these sites). These sites suffered from the drought of 2013-2015, and abnormally warmer temperatures and significantly less fog (Johnstone & Dawson, 2010).

The estimated number of localities (including undiscovered ones) is less than 70, usually with small populations of 1-10 individuals each, less than 7,000 mature individuals in total.

Because of the limited reports, and understanding of this species, it’s tough to assess the trend. The greater part of suitable habitat within its distribution in California and Oregon has been lost during the last 100 years; due to logging, farmland development and urban sprawl. The continued decline of suitable habitat suggest that this species is deteriorating.

Population Trend: Decreasing

Habitat and Ecology

Hydnellum cyanopodim forms mycorrhiza Sitka Spruce and grows in open understory of mature/old growth, mossy forests on the immediate coast.


Global climate change is potentially devastating to coastal Sitka Spruce forest; especially in the southern part of the range, where this fungus is most prevalent. These trees depend on summer fog and winter rains. Due to climate change, the fog patterns have changed considerably during the last 100 years with a significant decrease of extent of fog in summer (Johnstone & Dawson, 2010), and winter rains are inconsistent during the last 10 years. Dryer, hotter summers and loss of fog is stressing southern populations of Sitka Spruce.

Coastal forests have been extensively logged for timber during the last century and logging is ongoing, resulting in fragmentation of available habitat. Forest understory vegetation has changed during the last 30 years, with an increase of Polystichum, Gaultheria shallon and Vaccinium ovatum, resulting in a decrease of open forest with a mossy substrate.

Continued coastal urban development, especially in Oregon will fragment habitat and contribute to habitat loss.

Conservation Actions

Most known locations are on protected federal and state park lands, but park managers should be made aware of this species.

Research needed

Confirmation that it occurs in Alaska is critical to establish if the unsubstantiated records are this species, or if it is restricted from northern CA and OR. Because of the distinctive and showy color and long lasting sporocarps, this would be a good species to get citizen scientists to look for additional locations in CA and OR, and try to locate populations in Washington and British Columbia.

Use and Trade


Siegel, Noah & Christian Schwarz (2016) Mushrooms of the Redwood Coast. Ten Speed Press 608p
Harrison KA. (1964). “New or little known North American stipitate Hydnums”. Canadian Journal of Botany 42 (9): 1205–33.
Johnstone JA, Dawson TE, 2010. Climatic context and ecological implications of summer fog decline in the coast redwood region. PNAS 107: 4533–4538.

Known distribution - countries

Regional Population and Trends

Country Trend Redlisted