Chroogomphus rutilus

Description

Chroogomphus rutilus is a little valued edible mushroom wich found beneath pine trees, with which it forms ectomycorrhizas. The copper-brown cap of this attractive fungus is slimy when wet and dries to a bright glossy copper sheen. This mushroom habitat in Europe and the USA.

Gomphidius Viscidus is an old synonym of this mushroom.

Common names: Brown Slimecap, The Copper Spike.

Mushroom Identification

1. Cap

   4-10 cm, initially hemispheric, then conical-campanulated, finally flat and also more or less depressed, with umbo; margin initially adherent to the stem, involute, then curved downwards and only belatedly outstretched. Smooth cuticle, viscous when the weather is humid, bright when the same is dry, fibrillose, of gray-brown, ochre-brown, vinous, color, with copper reflexes or olivaceous shades.

2. Hymenium

   Thin gills, decurrent on the stem, thick, arcuate, intercalated by lamellas; the color goes from the olive ochre, olive-green to the blackish-brown when ripe.

3. Stem

   5-10 x 1-2 cm, slender, cylindroid, attenuated at the base, full; surface rather viscid, fibrillose, with thin scales arranged in a zigzag, concolorous to the cap, more wine-red in the upper part, yellowish at the base, at times decorated with remnants of the veil which form an annular zone in the upper part in the young fungus.

4. Flesh

   The firm, compact, mushy when ripe, fibrous in the stem, of orange-ochre, salmon-pink, color, finally, in the ripe specimens, also wine-red, yellow, or chrome-yellow at the stem base. No distinct smell, mildly nutty flavor.

5. Habitat

   Quite common species, it grows, in summer and autumn, under two-needle pines: Pinus pinea in the Mediterranean environment; Pinus nigra and Pinus sylvestris in the mountains.

6. Spores

   Brownish at the microscope, spindle-shaped, ellipsoidal, smooth, guttulate, (13)-15-19 × 6-7,5 µm.

7. Basidia

   Clavate, tetrasporic, without joint-buckles, 50-63 × 11-14,5 µm.

8. Cheylocistidia and Pleurocystidia

   Numerous, cylindroid, just ventricose, encrusted, 127,5-147,5 × 15-20 µm. Bilateral lamellar texture. Olive-brown spores in mass.

Look-Alikes

1. Chroogomphus fulmineus

   Is a southern European species with bright orange tones, a very fibrous stem surface, and a cap that rarely has a central pip.

2. Gomphidius glutinosus

   Is a much rarer find and occurs under spruce trees; its cap is gray-violet and its stem is white near the cap and lemon grey towards the base. A glutinous zone at the apex of the stem gradually blackens with age.

History

First described scientifically in 1774 by Jacob Christian Schaeffer, who gave it the binomial scientific name Agaricus rutilus (at a time when most gilled fungi were initially placed in the genus Agaricus - since redistributed), this species was transferred to the genus Chroogomphus in 1964 by American mycologist Orson K. Miller, Jr., (1930 - 2006).

Chroogomphus rutilus is the type species of the genus Chroogomphus and the only member of that genus known to occur in Britain and Ireland. Other so-called Spikes are found in Britain, but they belong to the related genus Gomphidius - Gomphidius glutinosus are two such examples. Although they have gills rather than pores, fungi in the family Gomphidiaceae are more closely related to the boletes than to the agaricales - inkcaps, webcaps, waxcaps, true mushrooms (Agaricus species), etc. Within the Boletales, the 'spikes' are more closely related to Suillus than to Boletus, which may partly explain their mycorrhizal preference for pine trees.

Chroogomphus comes from the Greek 'gomphos', a large conical (wedge-like) nail or bolt with a large head, made of either metal or wood and used mainly in ship-building. The prefix "chroo-" means color. The conical shape of the fruitbodies means that they look very much like those ancient bolts.

The specific epithet rutilus means shining red or golden - quite appropriate for these brilliantly polished caps.

Synonyms

1. Agaricus rutilus Schaeff.

2. Agaricus gomphus Pers.

3. Cortinarius rutilus (Schaeff.) Gray

4. Gomphidius rutilus (Schaeff.) S. Lundell & Nannf.

5. Gomphidius viscidus f. giganteus J. E. Lange

6. Chroogomphus rutilus var. rutilus (Schaeff.) O.K. Mill.

7. Chroogomphus corallinus O.K. Mill. & Watling

8. Chroogomphus britannicus A.Z.M. Khan & Hora

9. Chroogomphus rutilus var. corallinus (O.K. Mill. & Watling) Watling.

Photo sources:

Photo 1 - Author: Holger Krisp (CC BY 3.0)

Photo 2 - Author: Alberto Vasquez (CC BY-SA 2.5)

Photo 3 - Author: Strobilomyces (CC BY-SA 3.0)

Photo 4 - Author: B.gliwa (CC BY-SA 2.5)

Photo 5 - Author: Eric Steinert (CC BY-SA 3.0)