The fungus is zonate, with concentric bands of color sometimes apparent on its cap, ranging from white, to grayish violet, to pastel blue zones.

Pale white or gray spines (3-6mm in length) cover the decurrent toothed hymenium on the stipe and underside of the cap.

During periods of high humidity, H. caeruleum can develop yellow liquid drops on actively growing pilei.

Additionally, cool late-September temperatures can lead the fungus to develop deeper blue colors during this time.

The species is commonly found in pine and spruce ecosystems due to its mycorrhizal relationships with coniferous trees.

[10] In these relationships, the fungus receives nutrients from the tree and in turn assists the plant in water and mineral uptake.

A study from 2012 suggests that stipitate hydnoid fungi such as H. caeruleum can remain in soils 1-4 years after their sporocarps are gon due to persistent below-ground mycelium.

The study suggested that this finding is important for the field of fungi and tree conservation, as H. caeruleum could survive even after a deforestation event and assist in the eventual reforestation of its habitat.

[12] While the fungus is not edible for humans, H. caeruleum’s unique coloration makes it a prized species for mushroom dyers.