Field key to GOMPHIDIACEAE in the Pacific Northwest

Prepared for the Pacific Search Magazine (March 1975) and
Adapted for the Pacific Northwest Key Council (March 1980)
By Kit Scates
Copyright © 1980, 2007 Pacific Northwest Key Council

Reformat and minor update Ian Gibson 2007

 

INTRODUCTION

The Gomphidius Family is easily learned, and all species are edible. Several characteristics make the Gomphidiaceae easy to recognize. The first and most obvious is the name which, like most Latin scientific names, is an attempt to describe it. Gomphidius means "little stake" or "peg" and refers to the shape of the young mushrooms with rounded caps and long, central stems that taper to a blunt tip at the bottom, very much like wooden tent stakes. The caps become convex and finally more or less depressed in age.

The second and surest feature of identification is the gills and spore print. There are very few mushroom genera which make black or blackish spore prints. Of those few, only one family, Gomphidiaceae, has gills which are decurrent, that is, the gills extend down the stem for one-half to two inches. Under the microscope the spores are mostly large and spindle-shaped. The Gomphidiaceae grow on the ground in woods in association with conifers.

For a time all species were lumped under the original genus, Gomphidius. During years of research, Dr. Orson K. Miller, Jr., professor of biology at Virginia Polytechnical Institute, determined that one section contained sufficient chemical and microscopic differences to warrant separate generic rank. This new genus is called Chroogomphus (pronounced crow-oh-gom-fus).

Fortunately visual differences are apparent to mushroom hunters who do not have the use Of a microscope.

Gomphidius and Chroogomphus species have neither volvas nor skirtlike rings, although most species have a veil when young which leaves a fragmentary ring on the stem of the mushroom as it matures.

In cross-section the gills are thick, distant, and waxy. The range of viscidity is great and helps to separate the species into smaller groups. Viscid describes mushrooms that have a layer of gelatinlike cells in the skin of the cap or stem that react like gelatin crystals. When there is much moisture available, they are slimy. After a dry spell they become dry and shiny like a varnished surface. This gluten should be wiped off before cooking the mushrooms. All species of Gomphidius are gelatinous in greater or lesser degrees, but the species of Chroogomphus are less so, some being viscid, some subviscid, some dry and fibrillose-scaly.

The species of Gomphidius, when very young, have caps with white or pale gray flesh inside, and the gills answer to the same description. Species of Chroogomphus have cap flesh and gills with yellow-buff, dull orange, or winey-red coloration.

In addition, most of the species of Gomphidius have a white column in the stem below the cap extending to a bright yellow base, while most Chroogomphus have stems in the same color series as the caps and lack the bright yellow base.

It is not necessary to tell the species apart to eat them, provided you have determined that the mushrooms have decurrent gills and leave a blackish spore print. But practice identifying the species, for safety, and just for the challenge of it.

 

UPDATE 2007

Mention of several other species has been added in the REMARKS with individual species. Gomphidius smithii is an important addition, but the others are all uncommon to rare. Gomphidius loculatus is another rare species with gill structure very interveined to loculate (chambered). The REFERENCES were also added.

 

MACROSCOPIC KEY TO GOMPHIDIACEAE

 

1a Cap flesh and gills white or pale, watery gray when young (Gomphidius)

1b Cap flesh and gills dull yellow, salmon or winey when young (Chroogomphus)

2a Lacking a veil when young

................................................................................Gomphidius maculatus

CAP 1-11 cm, glutinous, light cinnamon to reddish brown, darkening from age or handling. STEM white at apex, moist to dry, base with or without yellow ground color underneath coating of dull yellow to purplish fibrils which blacken with age or handling. SPORES in mass smoke-gray to nearly black, 14-22 x 6-9 um. HABITAT conifers, especially larch.

2b Having a veil when young, usually glutinous or gelatinous

3a Cap pink, rose or red

................................................................................Gomphidius subroseus

CAP 4-6 cm broad, glutinous, glabrous (without hairs); flesh thick in center but thin at edge. GILLS subdistant (fairly well separated). STEM 3.5-7 cm long, 0.6-1.8 cm in diameter, tapering slightly toward base, white and silky above ring, deep yellow below "ring" left from separation of thin, slimy veil. SPORES in mass black, 15-21 x 4.5-7 um. HABITAT mixed conifers.Gomphidius subroseus
Gomphidius subroseus
Steve Trudell

3b Cap salmon, reddish-brown or winey-gray

4a Fruiting bodies usually growing several stuck together (some may be aborted) from deep in soil

................................................................................Gomphidius oregonensis

CAPS 2-15 cm broad, dingy salmon to winey-gray, glutinous; flesh thick, soft and spongy, lacking distinct odor or taste. STEM 6-12 cm long, 1-5 cm in diameter, often partly buried and growing from large, firm, fleshy body, glutinous below annular zone, gluten often darkening; base often deep yellow. SPORES black in mass, 10.5-13 x 4.5-8 um. HABITAT under conifers generally. REMARKS Gomphidius pseudomaculatus is very rare, differing in having no glutinous veil, wider cuticular hyphae, and some of caulocystidia thick-walled.Gomphidius oregonensis
Gomphidius oregonensis
Michael Beug

4b Fruiting bodies usually gregarious or single, only caespitose occasionally and then lacking tuberous growth

................................................................................Gomphidius glutinosus

CAP 2-10 cm broad, glutinous, lacking hairs, smooth, purple-brown or winey-gray or dingy salmon, often developing blackish spots; flesh thick, soft, pallid. STEM 4-10 cm long, 0.7-2 cm in diameter, tapering toward base which is usually yellow; veil leaves a sticky band which is soon black from spores. SPORES in mass smoke-gray to black, 15-21 x 4-7.5 um. REMARKS Gomphidius smithii is another rather common species that will key out here. The size is like G. subroseus but there is less red in the cap and less yellow in the stem. It is also less pigmented in the cap and less yellow in the stem than G. glutinosus. Gomphidius largus occurs at least in Idaho. It is like G. glutinosus except the large size attained (cap up to 21 cm broad), and inflated cellular gill trama (cap trama near gills partly cellular).Gomphidius glutinosus
Gomphidius Steve Trudell
Steve Trudell
Gomphidius smithii

                                                                                                                                                                                                                                   

Gomphidius smithii
Gomphidius smithii
Michael Beug
                                                                                                                                                                                                                                                                                                                                                   

5a (1b) Fruiting body entirely yellow-orange, inside and out

................................................................................Chroogomphus tomentosus

CAP 2-6 cm broad, dry and fibrillose, fibrils sometimes with winey tinge; flesh light orange, firm. GILLS light orange or dull yellow-orange when young, becoming clouded from black spores in age. STEM 4-17 cm long, 0.9-1.4 cm in diameter, tapering, dry and slightly fibrillose; hairy veil n breaking leaves fibrils but no ring. SPORES smoke-gray to black in mass, 15-25 x 6-9 um. HABITAT under many different conifers. REMARKS A similarly colored, less common species without fibrils and somewhat viscid, with spores 14-20 x 4.5-7 um, is Chroogomphus ochraceus. Another species with a somewhat grayer cap but much less common than C. tomentosus and differentiated microscopically is Chroogomphus leptocystis. It has somewhat smaller spores 12-18 x 6-7 um, thinner walls on cystidia, and the cap cuticle hyphae are colorless, not amyloid, and distinctly narrower than the cap trama hyphae, whereas in C. tomentosus the hyphae of the cap cuticle are amyloid, mostly 7-9 microns wide, and the same size as the hyphae of the cap trama.Chroogomphus tomentosus
Chroogomphus tomentosus
Michael Beug

5b Fruiting body some other color, mostly reddish-brown or winey

6a Cap dry, smooth to velvety; stem unusually robust and patchy-fibrillose

................................................................................Chroogomphus pseudovinicolor

CAP large, 6-12 cm broad, thick, dull orange-red or winey-red, smooth or patchy from fine tomentum; flesh dull orange but becoming wine-colored around larval tunnels. STEM 6-9 cm long, 2-4 cm in diameter, bulging somewhat at ring just below apex; below ring much more fibrillose with fibrils in patches and colored more winey than smoother area above. SPORES in mass green to olive-black, 15-20 x 5-7.5 um. HABITAT usually under Douglas-fir or Ponderosa pine.Chroogomphus pseudovinicolor
Chroogomphus pseudovinicolor
Ben Woo

6b Cap viscid, drying shiny, surface smooth young but aging fibrillose; stem average to slender in diameter

7a Cap reddish-brown, often with acute umbo (knob); cystidia thin-walled

................................................................................Chroogomphus rutilus

CAP 2.5-12 cm broad, convex or convex with almost pointed, raised knob in center, margin incurved when young; flesh light salmon in cap to light yellow in base of stem. GILLS cinnamon, rather well separated. STEM 4.5-18 cm long, 0.5-2.5 cm in diameter, dry to moist, slightly fibrillose, orange-buff with reddish cast; dry hairy veil leaves a thin hairy line which may catch black spores. SPORES in mass smoke-gray to black, 14-22 x 6-7.5 um. HABITAT usually under pines.Chroogomphus rutilus
Chroogomphus rutilus
Kit Scates Barnhart

7b Cap dark reddish- or orange-brown to wine-colored, almost conical in shape; cystidia thick-walled

................................................................................Chroogomphus vinicolor

CAP viscid, drying shiny, glabrous (without fibrils) except at margin, bruising white-color; veil of dry, dull yellow fibrils breaks and fibrils slowly become more orange than ground color or stem; cap flesh orange throughout, becoming wine-red when bruised. GILLS more distant than most, pale yellow-orange becoming clouded from spores in age. STEM comparatively slender, orange-buff aging winey. MICROSTRUCTURES spores olivaceous-black to black in mass, 17-23 x 4.5-7.5 um; cystidia, or large, sterile cells on gills, have very thick walls in their mid-portions. HABITAT usually under pines.Chroogomphus vinicolor
Chroogomphus vinicolor
Kit Scates Barnhart

 

REFERENCES

  1. Arora, David. 1986 Mushrooms Demystified Second Edition. Ten Speed Press, Berkeley.
  2. Miller, Orson K. 1964. "Monograph of Chroogomphus (Gomphidiaceae)." Mycologia 56: 526-549.
  3. Miller, Orson K. 1970. "A new Chroogomphus with a loculate hymenium and a revised key to Section Floccigomphus." Mycologia 62: 831-836.
  4. Miller, Orson K. 1971. "The genus Gomphidius (with a revised description of the Gomphidiaceae and a key to the genera." Mycologia 63: 1129-1163.

 

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