Hydnum rufescens

What You Should Know

Hydnum rufescens is an easily identified edible mushroom with a great taste that grows in many types of woodland. It belongs to the small group of mushrooms often referred to as the tooth fungi, which produce fruit bodies whose cap undersurfaces are covered by hymenophores resembling spines or teeth, and not pores or gills.

This mushroom has a red-orange-colored lighter towards the edges. It has a fine woolly texture with unevenly lobed edges and quite often, the cap sits eccentrically on the stem.

It is very similar to the commoner hedgehog fungus (Hydnum repandum), and was previously sometimes considered a variety of that species. However, the following differences have been noted:

1. The cap of H. rufescens is russet rather than beige.

2. The overall dimensions are smaller and more regular in shape, with a central stipe.

3. The spines are not decurrent, and the spores are slightly larger.

Both species are found in European coniferous and deciduous forests growing on soil. It is reportedly ectomycorrhizal with Picea abies, Pinus sylvestris, Fagus sylvatica, and Quercus robur.

Other names: Terracotta Hedgehog

Hydnum rufescens Mushroom Identification

1. Cap

   The cap is 2 to 6 cm in diameter orange-red or pale tan, smooth and slightly felty to the touch; it is often perched eccentrically upon the stipe. The flesh is pink.

2. Spines

   Hanging down like stalactites, soft spines cover the fertile surface beneath the cap. Unlike those of its close relative, Hydnum repandum, the pink spines of this species are adnexed or almost free rather than decurrent to the stem. When fully developed, the spines are 2 to 4mm long.

3. Stem

   Pinkish white and solid with white flesh, stems of the Terracotta Hedgehog are 2 to 4cm tall and typically 1.5 to 3cm in diameter.

4. Spores

   Ellipsoidal, smooth, 6.5-8 x 5.5-7μm.

5. Spore Print

   White.

6. Odor and Taste

   Odor not distinctive; the taste is initially mild but turns bitter in the mouth after a few moments delay.

7. Habitat & Ecological Role

   Ectomycorrhizal with conifers and probably also with broadleaf trees; often forming rings or arcs among the moss and leaf litter of the forest floor.

8. Similar Species

   Hydnum repandum is larger and cream-colored; its spines are decurrent to the stem rather than adnexed.

Hydnum rufescens Taxonomy and Etymology

In 1801, when Christiaan Hendrick Persoon described this mushroom, he gave it the binomial name Hydnum rufescens, which still is its generally accepted scientific name.

Synonyms of Hydnum rufescens include Dentinum rufescens (Pers.) Gray, and Hydnum repandum var. rufescens (Pers.) Barla.

Hydnum, the genus name, comes from the Greek noun udnon or hudnon, a truffle. The specific epithet rufescens means becoming rufous (reddish-brown).

Sources:

Photo 1 - Author: Jerzy Opioła (Creative Commons Attribution-Share Alike 4.0 International)

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