Hydnellum scrobiculatum

Description

Hydnellum scrobiculatum is an inedible tooth fungus in the family Bankeraceae. It can be recognized by a fibrillose to pitted-scaly, brown to reddish-brown cap with paler, often zonate margin, short buff-brown spines, brown to reddish-brown context tissues, and a mild or faintly farinaceous odor and taste. Often there are so many fruit bodies in proximity that the caps and even the stems become fused; however, when well-spaced they produce rosettes with colorful ridged margins and contrasting centers.

Widely distributed in the Northern Hemisphere, it is found in Asia, Europe, and North America.

Common names: Ridged Tooth, Rough Hydnellum.

Mushroom Identification

1. Cap

   The cap initially flat-topped becoming slightly funnel-shaped with a thin margin; 3 to 6cm in diameter and 1 to 3cm tall; cap flesh thin (<2mm); upper surface concentrically zoned; pink at the margin, darker reddish-brown or rusty cinnamon in the center; cap flesh tough and fibrous.

   The underside of the cap is covered with crowded, purplish-brown spines 1 to 3mm long. Spines are decurrent to the stem

2. Stem

   Range from 0.5 to 3cm in diameter and are up to 4cm tall, slightly swollen at the base; color as the center of the cap.

3. Spores

   Irregularly ellipsoidal to subglobose, 4.5-6.5 x 4-5µm; ornamented with irregular coarse warts; inamyloid.

4. Spore Print

   Dull brown.

5. Odor and Taste

   No significant odor; taste mild, slightly farinaceous.

6. Habitat & Ecological Role

   In mixed woodland, mycorrhizal with pines, growing in the debris of the forest floor; also occasionally found under broadleaf trees.

Look-Alikes

1. Hydnellum concrescens

   Very similar but is found under oak and Sweet Chestnut trees in southern Britain but often with conifers in Scotland; it has slightly larger spores.

2. Hydnum rufescens

   Tan colored without concentric zones; its spines are adnate to the stem rather than decurrent.

3. Hydnellum aurantiacum

   Has a more coarsely lumpy-nodulose cap with bright rusty to cinnamon colors and brighter orange to orangish brown context tissues.

History

Tooth fungi of various kinds can be found in many taxonomic orders, and over the years their - Classification has changed considerably. The basionym of Ridged Tooth was set in 1815 when this species was described scientifically by the great Swedish mycologist Elias Magnus Fries, who gave it the binomial name Hydnum scrobiculatum - effectively implying a close relationship with the Wood Hedgehog and the Terracotta Hedgehog fungi, which also have teeth on their fertile cap surfaces (the undersides).

It was not until 1880 that this woodland fungus obtained its currently-accepted scientific name Hydnellum scrobiculatum, when Finnish mycologist Petter Adolf Karsten (1834 - 1917) transferred the Ridged Tooth into the genus Hydnellum, which Karsten himself had circumscribed in the previous year.

Synonyms of Hydnellum scrobiculatum include Hydnum scrobiculatum Fr., and Hydnellum velutinum var. scrobiculatum (Fr.) Maas Geest.

Hydnellum, the generic name, is derived from the ancient Greek word hudnon, meaning an edible mushroom; this term was applied particularly to edible truffles.

The specific epithet scrobiculatum means scrobiculate (pitted).

Photo sources:

Photo 1 - Author: Dan Molter (shroomydan) (CC BY-SA 3.0)