A Skeleton Trial Key to TRICHOLOMA in the Pacific Northwest

Prepared for the Pacific Northwest Key Council
by Coleman Leuthy 1996
Copyright © Pacific Northwest Key Council 1996, 1997

INTRODUCTION

This key is a trial field key to species reported in the Pacific Northwest. Work on it is ongoing, by Coleman Leuthy and Andrew Parker. Descriptions will eventually be added.

The species marked with an asterisk need confirmation for the Pacific Northwest and some of them will not be included in the final key.

I Annulus present:

................................................................................Group 1

II Having a strong odor:

................................................................................Group 2

III Color of cap:

A White to pale or pastel

................................................................................Group 3

B Green &/or yellow to orange or reddish orange but not brown or other reds

................................................................................Group 4

C Reddish brown or brown but not gray – black in the base color, fibrils may be +/- black

................................................................................Group 5

D Gray to black, especially fibrils, etc.

................................................................................Group 6

* These species need confirmation for the Pacific Northwest and some of them will not be included in the final key.

KEY TO TRICHOLOMA

Group 1 – Species with an annulus – 8 species

1a Cap surface entirely some shade of yellow

................................................................................2

1b Cap surface not entirely yellow, or some other color

................................................................................3

2a Cap with brownish to blackish radiating fibrils, without upturned scales, surface slightly viscid only when moist. Armillaria albolanaripes =

................................................................................Floccularia albolanaripes

2b Cap with light colored, upturned scales, surface moist and sticky. Armillaria luteovirens =

................................................................................Floccularia luteovirens

3a (1b) Cap surface bright orange; stem uniformly orange below with almost concentric scale-flakes around the mid-portion, the upper part white

................................................................................T. aurantium

3b Cap surface orangish and/or of other colors

................................................................................4

4a Cap surface orangish, reddish orange to chestnut or date brown often with green tones; stem tapering at base

................................................................................5

4b Cap surface either gray, or white to whitish gray with flattened fibrils; fibrils grayish or cinnamon-brown to chestnut or vinaceous

................................................................................6

5a Cap orange to orange brown, often lighter on the margin, at times showing some olive-green tints; strong farinaceous smell especially when split open; stem short and stout, tapering at the base. Armillaria zelleri = Tricholoma zelleri =

................................................................................T. focale

5b Cap chestnut to coppery or reddish brown; stem longer and cylindrical, tapering at base; known from Europe and Japan, not known to occur in North America

................................................................................T. robustum

6a (4b) Cap gray, brownish or bluish

................................................................................7

6b Cap white and or with few to nearly covered by brown fibrils so as to appear brown

................................................................................8

7a Cap gray to bluish gray sometimes developing olivaceous tones, sometimes overlaid with white cottony or fibrillose veil remnants forming a patch in center of cap; smell distinctive of cucumber or watermelon rind. Armillaria olida =

................................................................................T. olidum

7b Cap gray-beige to gray-brown, yellowing in age, smooth to finely and radially fibrillose; odor farinaceous - mealy

................................................................................T. cingulatum

8a (6b) Cap white, sometimes streaked or with splotches of brown (? grayish to grayish brown); a robust species with cap 8 - 20 cm or larger; stem expanded at base often with brown streaked areas; odor distinctly spicy-aromatic. Armillaria ponderosa = T. ponderosum =

................................................................................Tricholoma magnivelare

8b Cap base color white, but cap appearing deep brown by flattened cinnamon-brown to chestnut or vinaceous fibrils, sometimes separating in age revealing a whitish or pinkish flesh; stem also covered with brown fibrils; smaller and more slender cap 4 - 12 cm broad; odor spicy-aromatic. Armillaria caligata =

................................................................................T. caligatum

Group 2 – Species with a strong odor – 6 species

1a Cap reddish brown to purple reddish brown

................................................................................T. bufonium

1b Cap white to yellow

................................................................................2

2a Odor of coal tar gas – sulfur aromatic, noxious somewhat sweetish

................................................................................3

2b Odor fruity of of jessamine or coconut

................................................................................5

3a Cap, gills, stem, and flesh yellow

................................................................................T. sulphureum

3b Cap whitish to pale yellow gray or yellow buff

................................................................................4

4a Cap dingy white to pale yellow gray; gills white sometimes blackening; stem whitish yellow, can brown at base

................................................................................T. inamoenum

4b Cap white to yellow buff; gills white to light buff, on aging dark yellow; stem whitish

................................................................................T. platyphyllum

5a (2b) Does not bruise yellow; odor of jessamine blossoms to nutty and farinaceous; cap grass yellow to yellow with a brown center; gills yellow fading to buff; stem yellow fading to buff, bruising brown at base

................................................................................T. odorum

5b Gills and stem spotting yellow when touched; odor fruity or coconut, nutty and somewhat acrid; cap white with yellow to orange yellow patches; gills white to cream yellow

................................................................................T. sulphurescens

Group 3 – CAP white – pale, pastel (see also the strongly odorous species in Group 2)

1a Cap to 4 (5) cm

................................................................................2

1b Cap to 7 or 8 cm

................................................................................3

2a Cap white with a bluish tint, centered blackish, prominent umbo

................................................................................T. subluridum

2b Cap white, subumbonate

................................................................................T. farinaceum

3a (1b) Cap whitish, dry, glabrous

................................................................................T. silvaticum

3b Cap cream to dingy white with fine brown to gray fibrils. A white form of Tricholoma scalpturatum (see Group 6)

Note: Tricholoma argyraceum, T. inocybeoides, and T. myomyces var. alboconicum were synonymized into T. scalpturatum (Guilden 1992)

Group 4 – CAP green and/or yellow to orange or reddish orange – 10 species

1a Cap green or with a green component

................................................................................2

1b Cap yellow to orange (may have some light green)

................................................................................5

2a Cap pale dull aquamarine “Tea Green” (R) 28D5 (Methuen), surface smooth, glabrous, viscid when wet; odor offensive (sour dish rags & Fels Naptha soap); taste unpleasant, astringent

................................................................................Undescribed or = Hygrophorus caeruleus

2b Cap green with other color components

................................................................................3

3a Cap light yellowish green, greenish yellow with brown disc and often elsewhere

................................................................................T. aestuans

3b Cap orange or olive or green gray, viscid to lubricous

................................................................................4

4a Cap olive to orange; annulus or remnant on stem

................................................................................T. aurantium

4b Cap green to gray; no annular remnant evident; base of stem showing pink

................................................................................T. saponaceum

5a (1b) Cap yellow, may have a green component, orange, brown, & or gray

................................................................................6

5b Cap yellow with orange, brown, grayish, or black component

................................................................................8

6a Cap viscid; cap, stem, and gills yellow; in age may be greenish yellow to vivid lemon yellow

................................................................................T. flavovirens

6b Cap dry, yellow and or orange to brown or gray

................................................................................7

7a Cap with a low broad umbo; odor absent (see 3a.)

................................................................................T. aestuans

7b Conic with a prominent acute umbo; odor farinaceous; stem vinaceous toward base

................................................................................T. davisiae

8a (5b) Cap orange to orange yellow or yellowish brown or pale tan

................................................................................9

8b Cap yellow with browns, brown-gray to blackish

................................................................................10

9a Cap viscid; odor farinaceous; an annulus or remnant present

................................................................................T. aurantium

9b Cap dry; odor none

................................................................................T. psammopus

10a (8b) Cap yellow with brown gray to blackish component

................................................................................11

10b Cap yellowish with browns, reddish brown

................................................................................12

11a Cap medium yellow, disk brownish gray

................................................................................T. subluteum

11b Cap blackish brown, margin often yellow or greenish yellow

................................................................................T. subsejunctum

12a (10b) Cap dry, yellowish-brownish, disc brown; odor absent (see 3a.)

................................................................................T. aestuans

12b Cap viscid to lubricous, brownish yellow; odor farinaceous

................................................................................T. sejunctum

Two varieties are noted: T. coryphaeum (Fr.) Gillet = T. sejunctum var. coryphaeum, and T. intermedium Peck = T. sejunctum var. intermedium. This is intermediate between T. sejunctum and T. flavovirens.

Group 5 – CAP reddish brown or brown – 11 species

1a Cap fibrillose to scaly to the touch, dry

................................................................................2

1b Cap smooth to the touch (but may be innately fibrillose), moist to viscid in rainy weather

................................................................................5

2a Cap color yellowish brown

................................................................................3

2b Cap color reddish brown

................................................................................4

3a Cap with radially aligned fibrils, appressed when young but becoming scaly in age; usually under larch

................................................................................T. psammopus

3b Cap with fibrils arranged +/- in concentric rows of appressed scales; usually under hardwoods

................................................................................T. venenatum

4a (2b) Young buttons with cortina; stem generally hollow; habit usually gregarious or cespitose; cap color reddish brown (rusty brown), buff ground color between scales readily apparent; cap surface broken into distinct scales

................................................................................T. vaccinum

4b Young buttons lacking cortina; stem generally solid; usually solitary or scattered; cap color duller, darker brown, ground color not readily apparent

................................................................................T. imbricatum

5a (1b) Gills and stem flesh yellow; stem surface fibrillose, yellow to brownish; cap margin striate when young. T. flavobrunneum =

................................................................................T. fulvum

5b Gills and stem flesh white to pallid, maybe spotting rusty red-brown in age

................................................................................6

6a Always growing under trees in the genus Populus (poplars, cottonwoods, aspens, etc.)

................................................................................T. populinum

6b Habitat with either conifers or hardwoods, but not limited to Populus species

................................................................................7

7a Cap color dirty yellowish brown; cap shape subconic; surface smooth but innately fibrillose and virgate, viscid but soon dry

................................................................................T. subumbrinum

7b Cap color reddish brown; cap shape not subconic, other features various

................................................................................8

8a Cap margin usually spotted with drops or dark spots, cap and gill edges blackening in age; odor mealy; stem usually short; usually with pines or spruce

................................................................................T. pessundatum

8b Cap lacking dark spots described above; other features varied

................................................................................9

9a Odor mild; usually with deciduous trees; cap red-brown with olivaceous tinge and blackening in age; gills white, then rust-spotted, old edges blackening

................................................................................T. ustale

9b Odor not farinaceous; usually under conifers, especially pines

................................................................................10

10a Stem apex clearly delimited by a pseudoannular white zone, length average; cap margin obscurely striate. T. albobrunneum (Pers. ex Fr.) Kummer =

................................................................................T. striatum

10b Stem with longitudinal fibrils sometimes cracking to form transverse bands but lacking real annular zone; stem rather tall and slender, +/- pointed at base; cap not striate

................................................................................T. stans

Group 6 – CAP gray to black or the primary color of the fibrils, etc. – 19 species

1a Cap viscid

................................................................................2

1b Cap dry

................................................................................5

2a Cap or fibrils with gray to black or gray brown

................................................................................3

2b Cap white to gray or cream

................................................................................4

3a Cap glabrous, 3 - 7 cm

................................................................................T. nigrocystidium Ovrebo nom. prov.

3b Cap with dark gray fibrils over yellow gray, 6 - 15 cm

................................................................................T. portentosum (Fr.) Quél.

4a (2b) Cap light-medium gray, may have large irregular white areas, broadly convex to +/- plane, often with a low umbo, disc dark brownish gray

................................................................................T. mutabile Shanks

4b Cap brown gray to olivaceous, cream brown, or white, somewhat conical prominent umbo, disc dusky brown, margin wavy

................................................................................T. umbonatum

5a (1b) Mature cap of larger expanded specimens over 10 cm (10 - 20 cm) broad

................................................................................6

5b Mature expanded caps less than 12 cm

................................................................................10

6a Innately interwoven radiating fibrils, scattered squamules, firm and short stature; stem 2.5-6 cm long, cortina in button stage; odor mild, taste bitter to acrid

................................................................................T. acre Peck

6b Fibrillose, scaly, or squamulose +/- upturned; stem mostly longer than 5 cm, no cortina; odor farinaceous, taste farinaceous or mild

................................................................................7

7a Cap, gills, or stem with violet or pinkish coloration or droplets

................................................................................8

7b Mushroom without pinkish or violet coloration

................................................................................9

8a Cap black violet gray, 6-13 cm; gills gray pinkish tinged; stem scattered squamules darkening to violaceous or +/- yellow, 6-15 cm long

................................................................................T. atroviolaceum Smith

8b Cap pale gray to darkish gray - pinkish, 6-9 (12) cm, often beaded drops of clear or pink fluid or streaked pinkish; stem silky to appressed fibrils, scales, often beaded with clear or pinkish drops of fluid, 4-8 cm long

................................................................................T. huronense Smith

9a (7b) Cap dark grayish brown to dull yellowish brown to nearly gray, 4-12 cm; gills light buff to light gray, in age often yellow, close; stem silky fibrils some projecting, 4-8 cm long

................................................................................T. luteomaculosum Smith

9b Cap with pale background, gray black to gray brown scales, 7-18 (20+) cm; gills dull white, +/- toothed; stem glabrous or smooth, base stains +/- yellow or rusty, 5-15 cm long

................................................................................T. pardinum (Pers.) Quél.

10a (5b) Cap, gills, or stem with pink, red, or violet tones, or bruising or becoming so in age or with clear pink - red droplets on cap edge or on stem

................................................................................11

10b No apparent coloration of pink, red, or violet to purple

................................................................................18

11a Gills white to gray, light gray buff, and with pinkish or reddish tones

................................................................................12

11b Gills white, dull white to gray, and or dingy buff to cream

................................................................................15

12a Cap with violet - violaceous tones (see 8a.)

................................................................................T. atroviolaceum

12b Cap dark brown gray - sooty gray

................................................................................13

13a Disc dark gray, gray-black, radially fibrillose-scaly +/- flushed pink, stem base reddish; after picking cap and gills turn reddish, bruised stem +/- turning reddish or green-blue

................................................................................T. orirubens Quéel.

13b Cap dark brown gray

................................................................................14

14a Stem drab light gray buff with a light ground color, silky fibrillose; taste bitter

................................................................................T. atrodiscum Ovrebo

14b Stem gray brown, color of cap, covered with squamulose fibrils; taste mild

................................................................................T. atrosquamosum var. squarrulosum Konrad & Maublanc

15a (11b) Cap conical, acute umbonate, light lilac tones, streaked surface, long innate radiating fibrils, silver gray - gray, stem white flushed pale pink, purplish pink at base, has a cortina, odor mild/absent, taste bitter

................................................................................T. virgatum (Fr. ex Fr.) Kummer

15b Cap convex to plane, with a low umbo or depressed

................................................................................16

16a Disc black, cap black-gray and with dark red-brown tomentose, scaly, fibrils, gills white-gray to dull cream, dotted black on edge, stem equal, pale gray, taste mild

................................................................................T. atrosquamosum (Chev.) Sacc.

16b Cap smoky gray or gray red brown

................................................................................17

17a Cap light smoke-gray to moderately pinkish, fibrillose gray cuticle becoming broken, appressed gray spotlike scales around disc and over margin, white flesh showing, often beaded drops of clear pink fluid or streaked pinkish along margin, gills dull white, stem clavate, silky and often pink beaded drops above, appressed-fibrillose scales below, pale gray, odor & taste farinaceous (see 8b)

................................................................................T. huronense Smith

17b Cap speckled salty gray-brown on a red-brown ground color, gray sooty-scaly, gills white to gray, stem center gray over slate, above and below pale, sparse cortina, odor weak fungoid, taste mild

................................................................................T. triste (Scop. ex Fr.) Quél.

18a (10b) Partial veil or cortina present but often fleeting - check buttons

................................................................................19

18b No evident cortina or veil

................................................................................24

19a Veil normally a persistent, flaring, cotton-membranous one that in age is often appressed to the stem, reticulate fibrils on cap surface likely part of the veil, white discoloring yellow

................................................................................T. cingulatum (Fr.) Jacobashch

19b Veil a cortina, not persistent

................................................................................20

20a Cap conic, acute umbonate silver gray to gray, stem base flushed pink to purplish pink (see 15a)

................................................................................T. virgatum

20b Cap more convex to low umbonate to plane or depressed

................................................................................21

21a Cap light medium gray, a firm good sized species (see 6a)

................................................................................T. acre

21b Cap darker to gray-blackish or brown

................................................................................22

22a With moderately spaced squamules, odor and taste farinaceous, veil a cortina of thin white fibrils, occasionally evident on stem for a brief time

................................................................................T. scalpturatum (Fr.) Quél.

22b Cap densely fibrillose-squamulose to granulose, odor and taste absent or week and mild

................................................................................23

23a Stem white to very pale gray, white to grayish surface fibrils projecting, silky; cap gray, dark drab to dark brown gray; veil a cortina, white to grayish fibrils, at times leaving a soon disappearing zone of fibrils on mid to upper stem

................................................................................T. myomyces (Pers. : Fr.) Lange

23b Stem gray over slate, mid to lower sooty-scaly, pale on upper and (lower) part; cap speckled salty gray-brown on red-brown (ochraceous) ground, gray sooty-scaly; veil a sparse cortina

................................................................................T. triste (Scop. ex Fr.) Quél.

24a (18b) Odor mild, aromatic - sweet/fruity, fungoid, or absent, taste mild or bitter

................................................................................25

24b Odor farinaceous, taste farinaceous, test with PDAB ( - )

................................................................................28

25a Odor sweet/fruity or mild, taste bitter and a positive test with PDAB (+) = bright pink all parts:

................................................................................

a Odor sweet/fruity. No chemical data, but mild odor & bitter taste here shows pattern of PDAB (+) (see 13a)

................................................................................T. orirubens

b Odor mild; cap gray silvery, generally with buff near edge, disc dense, margin with concolorous innate fibrils, streaked but not distinctly banded, stem white to sordid buff, stem silky-fibrillose with surface fibrils projecting, often pruinose at apex

................................................................................T. argenteum Ovrebo

c Odor mild (see 6a)

................................................................................T. acre

d Odor mild (see 14a)

................................................................................T. atrodiscum

e Odor mild (see 20a)

................................................................................T. virgatum

25b Odor mild, aromatic, or absent, taste mild, test with PDAB ( - )

................................................................................26

26a Odor mealy, aromatic peppery or of basil, slight or + farinaceous, fruity peppery, taste mild, slightly farinaceous-bitterish (see 16a)

................................................................................T. atrosquamosum

26b Odor mild or weak fungoid, taste mild

................................................................................27

27a Cap dark gray drab to blackish or dark brown gray, appresed fibrils + recurved or squamulose (see 23a)

................................................................................T. myomyces

27b Cap speckled salty gray brown on red brown ground with gray sooty scales (see 23b)

................................................................................T. triste

28 (24b) Cap convex to conical umbonate, disc almost black, margin almost slate black, dark to light gray - silvery or gray brown, finely tomentose, appressed innate radial fibrils to floccose then scaly, incurved and +/- crenate; stem white to gray white, smooth, apex floccose fibrillose, solid or persistently fibrous-stuffed, readily splitting lengthwise; cap and stem fragile

................................................................................T. terreum (Schaeff.: Fr.) Kumm.

Note that there are seven other species that may key out here:
T. atrosquamosum var. squarrulosum, see 14b.
T. atroviolaceum, see 8a.
T. cingulatum, see 19a.
T. huronense, see 8b.
T. luteomaculosum, see 9a.
T. pardinum, see 9b.
T. scalpturatum, see 22a.

Tricholoma apium Paul Kroeger	Tricholoma argenteum Michael Beug	Tricholoma atrosquamosum Ben Woo	Tricholoma atroviolaceum Andrew Parker
Tricholoma aurantium Michael Beug	Tricholoma bufonium Andrew Parker	Tricholoma caligatum Michael Beug	Tricholoma cingulatum Ben Woo
Tricholoma davisiae Andrew Parker	Tricholoma flavovirens Steve Trudell	Tricholoma focale Andrew Parker	Tricholoma fulvum Boleslaw Kuznik
Tricholoma imbricatum Michael Beug	Tricholoma inamoenum Andrew Parker	Tricholoma intermedium Andrew Parker	Tricholoma magnivelare Paul Kroeger
Tricholoma muricatum Steve Trudell	Tricholoma nigrum Steve Trudell	Tricholoma odorum Ben Woo	Tricholoma pardinum Andrew Parker
Tricholoma pessundatum Michael Beug	Tricholoma populinum Andrew Parker	Tricholoma portentosum Andrew Parker	Tricholoma saponaceum Boleslaw Kuznik
Tricholoma sejunctum Steve Trudell	Tricholoma subluteum Ben Woo	Tricholoma sulphurescens Andrew Parker	Tricholoma sulphureum Steve Trudell
Tricholoma terreum group Michael Beug	Tricholoma triste Michael Beug	Tricholoma vaccinum Andrew Parker	Tricholoma venenatum Ben Woo
Tricholoma vernaticum Michael Beug	Tricholoma virgatum Steve Trudell	Floccularia albolanaripes Kit Scates Barnhart	Floccularia luteovirens Kit Scates Barnhart

Copyright to each photograph is held by the person named under the photograph.

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