Trial field key to species of LENTINELLUS and NEOLENTINUS in the Pacific Northwest

Prepared for the Pacific Northwest Key Council
By Takeo Mochizuki (Puget Sound Mycological Society) October 1979
Copyright © 1979, 2002, 2007, 2019 Pacific Northwest Key Council
Photo copyright held by each photographer
Do not copy photos without permission

Reformat and minor revision Ian Gibson November 2002, 2007, 2019

TABLE OF CONTENTS

Note on revision

Introduction

Distribution table

Key to Species

Glossary

References

Index

NOTE ON 2002 REVISION

All included Lentinus species were transferred to Neolentinus. (Lentinus strigosus was not included in the original key as the current name was Panus rudis.) Lentinellus omphalodes was changed to Lentinellus micheneri. Lentinellus flabelliformis and Neolentinus adhaerens were added. Additional distribution records were inserted, a bibliography was added, and the format changed to conform to new standards.

NOTE ON 2007 REVISION

Additional information was added from Petersen & Hughes (2004). Lentinellus occidentalis and Lentinellus subargillaceus were added in remarks under Lentinellus flabelliformis. A note was added about Lentinellus castoreus under Lentinellus ursinus. Additional distribution records were inserted.

INTRODUCTION

The key contains species of the Lentinellus and Neolentinus found in the Pacific Northwest.

The genera Lentinellus and Neolentinus are keyed together because they have common features. All species of this group are found growing on wood. Some are found on hardwood only, others on conifer only and still others on both. The species are distinguished by their toothed (serrate) gill edges. N. kauffmanii develops the toothed gill edges at full maturity. The toothed gill edges vary from a sawtooth shape on the Neolentinus species to coarsely toothed to ragged on the Lentinellus species.

The spores of the species in the genera are white, except for the spores of Neolentinus lepideus and Lentinellus micheneri. N. lepideus spores vary from pure white to buff color and the spores of L. micheneri are buff color. The spore color of the rare Neolentinus adhaerens is not noted in the description.

Two major differences separate Lentinellus and Neolentinus. They are the spore shape and reaction of the spores to Melzer's reagent. The spores of Lentinellus species are almost round with fine spines and are amyloid in Melzer's. Neolentinus spores are smooth, elliptical and do not have an amyloid (blue) reaction in Melzer's reagent.

The stem of Lentinellus and Neolentinus is centrally located on some species, others are eccentric (off-center) or absent. Species usually fruit in the late Summer and Fall with the exception of Lentinellus montanus which fruits in the Spring or early Summer near snow. The species are not found commonly in this region except for N. lepideus and L. ursinus. N. lepideus is found commonly in Idaho and Washington and L. ursinus is found commonly only in Idaho.

Lentinellus and Neolentinus are a group of species that are not considered to be edible because of the toughness of their fruitbody or taste. Taste of many of the species is bitter or peppery. Lentinellus montanus is tough but has been reported to have good flavor. N. lepideus and N. ponderosus are considered edible only when young. None of the species in the genera have been reported poisonous. Table 1 shows the distribution and edibility of the species in this region.

TABLE 1 DISTRIBUTION AND EDIBILITY OF LENTINELLUS AND NEOLENTINUS SPECIES

Edibility based on color code used by Puget Sound Mycological Society:

Green for edible.

White for valueless (worthless as food, may taste unpleasant).

Yellow for caution (conflicting data, may have toxic properties).

Gray for unknown (no data on edibility).

Pink for poisonous.

1. material examined by Miller & Stewart 1971, but no direct indication of frequency

2. known from two sites in Washington, and from Europe according to Castellano et al. 1999

3. Ginns 1986

4. Castellano et al. 1999

5. Bessette 1995

6. Farr et al. 1989

7. known from two collections in Washington, one in Oregon, and one in California, Petersen & Hughes 2004

8. Petersen & Hughes 2004

9. Petersen & Hughes (2004) separate Lentinellus castoreus (examined from Washington, California and elsewhere) from Lentinellus ursinus (examined from Washington, Idaho, California, and elsewhere)

KEY TO SPECIES

1a Cap with stem

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

1b Cap without stem (sessile)

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2a Stem with ring (annulus) present

................................................................................Neolentinus lepideus

CAP 5-12 cm broad, convex or flat, sticky but dries with age, white to buff at first, breaks up into small coarse brownish scales and raised in age; flesh tough whitish, often aging or bruising yellow. ODOR anise-like, pungent or fragrant. TASTE somewhat disagreeable. GILLS decurrent, notched, adnate or adnexed, edges toothed when old, white to buff in age or in one form yellow, rusty brown or yellowish stains when bruised. STEM 3-10 cm long, 1-3 cm thick, equal, white and minutely hairy above ring, small scales (or fibrils) that curve outward develop in lower part, white to reddish brown in age. VEIL ring on stem but in age it may weather away. HABIT single to several. HABITAT on logs and stumps of conifers, occasionally hardwoods. EDIBILITY edible. MICROSTRUCTURES spores 7-15 x 3-6.5 um, long elliptical, smooth, thin-walled, not amyloid.

Neolentinus lepideus Steve Trudell

2b Stem with ring absent

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

3a Cap smooth

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

3b Cap not smooth, hairy or with scales or resinous patches

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

4a Stem more than 0.4 cm thick and more than 3 cm long at maturity

................................................................................Neolentinus kauffmanii

CAP 3-8 cm broad, thin convex to nearly flat, pinkish to tan, wine-colored tinge when fresh and moist; flesh rubbery-pliant. TASTE peppery. GILLS toothed at full maturity, decurrent, alternating gills, white to wine-colored. STEM 3-6 cm long, 0.5-1.2 cm thick, central to eccentric. HABIT solitary to scattered, rarely in small clusters. HABITAT along old conifer logs, for example Sitka spruce, forms a brown pocket-rot in the log. MICROSTRUCTURES spores 5-6 x 2-2.5 um, smooth, oblong to elliptical, not amyloid.

Neolentinus kauffmanii Michael Beug

4b Stem less than or equal to 0.4 cm thick or less than 1.8 cm long at maturity

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

5a Stem well-formed, central or slightly off-center

................................................................................Lentinellus micheneri

CAP 1-5 cm broad, flat to nearly flat with a central depression in age, moist but not sticky, pinkish buff becoming grayish brown in age; flesh soft, off-white. ODOR fungus-like. TASTE mild at first then peppery, or (according to Courtecuisse & Duhem) strongly bitter. GILLS adnate, finely toothed, pinkish brown. STEM 0.5-6.0 cm long, 0.05-0.4 cm thick, central to slightly off-center, with ridges and furrows, smooth, without hairs. Stem with white soft tissue in interior surrounded by firm, dense tissue. HABIT single or in small groups. HABITAT on woody debris, sticks or logs, stumps of conifers and hardwoods. MICROSTRUCTURES spores 4.5-6.5 x 3.5-4.5 um, short elliptical, amyloid, with minute spines.

Lentinellus micheneri Michael Beug

5b Stem when present laterally attached to distinctly off-center Lentinellus flabelliformis (see 10a)

6a (3b) Cap finely scaly and progressively covered with an amber resin which darkens and hardens with age, leaving polished shiny reddish brown patches, rare

................................................................................Neolentinus adhaerens

CAP 2-5 cm broad, slightly depressed or umbonate convex to flat, pale gray brown to dark yellow-red-brown, viscid (sticky) in patches, finely scaly, progressively covered with an amber resin which darkens and hardens with age, leaving polished shiny reddish brown patches, slightly pleated margin when young; flesh firm, tough, off-white to pale yellow-brown. ODOR pleasant or fungus-like. TASTE mild or bitter, astringent. GILLS short-decurrent, subdistant (between close and distant), cream becoming pale yellowish brown, occasionally stained reddish brown, with smooth to uneven finely fringed edges, weakly serrate to distinctly finely toothed. STEM 3-7 cm x 0.6-1.6 cm, central to eccentric, with club-shaped base, pale yellow brown darkening to dark gray brown at the base, occasionally staining reddish brown, hairy at top, becoming bald at base. HABIT single or in small groups. HABITAT on conifer wood or hardwood. MICROSTRUCTURES spores 7-11.5 x 3-3.5 um, smooth, oblong, not amyloid.

6b Cap hairy or with broad scales but without resinous patches

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

7a Cap hairy

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

7b Cap not hairy (but develops broad scales)

................................................................................Neolentinus ponderosus

CAP 10-30 (50) cm, convex becoming nearly flat with center depressed, white to tan or brownish, breaks up into broad brownish scales, margin cottony; flesh tough, white, may bruise yellowish. ODOR fragrant or not distinctive. TASTE mild. GILLS decurrent or adnate, narrow but broad in age, whitish to pale orange often staining orange to rusty brown, edges serrate or torn, at least at maturity. STEM 5-20 x 1-8 cm, central to eccentric, tapered down, white to buff at top, reddish brown lower down, with fine scales. HABIT single to several. HABITAT on logs and stumps of conifers, occasionally hardwoods. MICROSTRUCTURES spores 8-11 (12) x 4.5-5.5 um, elliptical, smooth, thin-walled, not amyloid.

Neolentinus ponderosus Boleslaw Kuznik

8a Cap less than 5 cm

................................................................................Lentinellus cochleatus

CAP 1-5 cm broad, irregularly funnel-shaped, tan to pinkish brown or reddish brown, moist, very brittle, with torn appearance, scattered hairs; flesh tough, watery, colored as cap. ODOR anise. TASTE strongly peppery. GILLS decurrent, thick, brittle, toothed, whitish to pale pinkish brown, may stain brownish. STEM 0.7-5.0 cm long, 0.3-3.0 cm wide, fused in clusters, dry, colored as cap or darker in lower part, ridged, but not from an extension of the gill edges. HABITAT found on hardwood sticks, logs and stumps, especially birch. MICROSTRUCTURES spores 4-5.5 x 3.5-4.5 um, nearly round, amyloid, minute spines.

8b Cap larger than 5 cm

................................................................................Lentinellus vulpinus

CAP 5-10(25) cm broad, shaped like a shell, evenly covered by downy cotton to woolly layer of short hairs, whitish to pinkish-brown; flesh soft, pliant; solid in stem. ODOR not distinctive. TASTE peppery. GILLS decurrent with thin ridges extending down the stem, roughly toothed, whitish becoming pale pinkish brown, staining brown when old. STEM short, stout, lateral, fused to form a large common base, light brown, dry, with a covering of short, soft, downy hairs, ridged by the decurrent gill edges. HABIT overlapping. HABITAT on fallen logs of birch and Populus, or wounds on living elm. MICROSTRUCTURES spores 3.5-4.5 x 2.5-3.5 um, nearly round, amyloid, with minute spines.

Lentinellus vulpinus Andrew Parker

9a (1b) Found near or under melting snow

................................................................................Lentinellus montanus

CAP 4-11 cm wide from side to side, 4.5-6.5 cm broad, shell-shaped to somewhat fan-shaped, convex to flat, moist but not sticky, center covered with long hairs, rest smooth, center dark brown to reddish brown, lightening towards margin; flesh tough, water-soaked, brown to light brown. ODOR none or slightly aromatic. TASTE mild to strongly peppery. GILLS coarsely toothed, gills alternating with shorter subgills, white, tinted purplish at first to buff when old. STEM absent. HABIT often in overlapping clusters. HABITAT on conifer logs, stumps, limbs, and twigs, usually at higher elevations in the spring or early summer near melting snow. MICROSTRUCTURES spores 4.5-6.5 x 4-5 um, nearly round, amyloid, thin-walled with spines.

Lentinellus montanus Ben Woo

9b Not found in the vicinity of snow

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

10a Buff or pinkish buff, usually on hardwoods

................................................................................Lentinellus flabelliformis

CAP 0.3-3.5 cm broad, petal-shaped to fan-shaped, convex becoming flat, or somewhat depressed near point of attachment, somewhat down-curved margin at first, surface smooth, buff or pinkish buff. ODOR none or slightly aromatic. TASTE somewhat farinaceous to slightly peppery. GILLS radiating, decurrent when a short stem is present, close to subdistant, broad (up to 0.5 cm), serrate to toothed, nearly colored as cap, pinkish buff. STEM usually absent, if present short (up to 1.8 cm long), eccentric to lateral, buff to pinkish buff. HABIT usually growing in clusters, in groups, or somewhat overlapping like shingles. HABITAT on bark or barkless sticks and logs of hardwoods, rarely conifer wood. MICROSTRUCTURES spores 4.5-7 x 3.4-5 um, nearly round to short elliptical, amyloid, with minute spines, gloeocystidia and leptocystidia present, pileocystidia absent, skeletalized (thick-walled) generative hyphae in trama. REMARKS According to Petersen and Hughes (2004) Lentinellus occidentalis is similar to Lentinellus flabelliformis but 1) spores are 4.7-6.2 x 3.6-4.5 microns, 2) pileocystidia are present on cap, and 3) generative hyphae are thin-walled, without skeletalized generative hyphae. Lentinellus subargillaceus was also often identified before its formal description as Lentinellus flabelliformis but is distinguished from other Lentinellus species by 1) small, conchate fruitbodies up to 3.2 cm broad, with or without a short lateral stem, 2) relatively large, elliptic spores 4.5-7.0 x (3.3)4.0-4.5 um, 3) gloeocystidia seen (but not leptocystidia), 4) prominent pseudopileocystidia (gloeoplerous hyphal tips on cap surface), and 5) prominent pseudocheilocystidia.

10b Dark brown, usually (in Pacific Northwest) on conifers

................................................................................Lentinellus ursinus

CAP 2-10 cm wide from side to side, 2-5 cm broad, shell-shaped with lobes, convex to nearly flat, minutely hairy to nearly smooth, matted to bristle-like hairs over the point of attachment, tan over margin, elsewhere dark brown; flesh thin, firm, white to pinkish buff. ODOR fairly strong, acid-fragrant, fruity, fungus-like, peculiar, or not distinctive. TASTE strongly peppery, (sometimes develops slowly after chewing), or bitter. GILLS coarsely toothed, whitish to pinkish buff. STEM absent. HABIT usually as several to overlapping clusters. HABITAT on logs and stumps, mostly of conifers in the Pacific Northwest, infrequently on oak or other hardwoods. MICROSTRUCTURES spores 3-4.5 x 2-3.5 um, nearly round to very short elliptical, amyloid, thin-walled with minute spines. REMARKS Lentinellus castoreus is treated by some authors as separate. According to Petersen & Hughes (2004) the following characters separate L. ursinus (and its forms) from L. castoreus: 1) fruitbodies of L. ursinus never have a pseudostem, while those of L. castoreus always have one; 2) gills of L. ursinus are broader (up to 5 mm broad) and less crowded than those of L. castoreus (never more than 2 mm broad), 3) taste of fruitbodies of L. ursinus is acrid [peppery], usually strongly and rapidly, while taste of fruitbodies of L. castoreus is hardly acrid, but anesthetic to the tip of the tongue, 4) skeletal hyphae of cap trama are moderately to strongly amyloid in L. ursinus, weakly so in L. castoreus, 5) gloeocystidia are common in the hymenium of L. ursinus, rare to absent in L. castoreus, 6) pleurocystidia are very rare in L. ursinus, present but variable in abundance in L. castoreus.

Lentinellus ursinus Ben Woo

GLOSSARY

adnate - (of gills) meeting the stem at right angles

adnexed - (of gills) narrowly attached to stem

amyloid - (of tissue or spores): a blue to violet reaction which takes place when an iodine solution (Melzer's reagent) is placed on the tissue or spore

annulus - ring on the stem resulting from the rupture of the inner veil

buff - (a color) a pale yellow toned with gray, that is, a dingy pale yellow

convex - (of cap) regularly rounded; broadly rounded

decurrent - (of gills) extending down the stem

farinaceous - with an odor like freshly ground wheat flour

furfuraceous - (of cap or stem) covered with branlike particles

fused - (of stem) two or more stems arising from a common base.

Melzer's reagent - a solution used to test for the amyloid (blue) reaction of fungal cell walls. It contains 20 cc of water, 1.5 gm. Of potassium iodide, 0.5 gm. of iodine and 20 gm. of chloral hydrate.

micron - one thousandth of a millimeter.

not amyloid - (of spore coverings) remaining clear or becoming yellowish in Melzer's reagent

notched - (of gills) curving up near stem then back down close to stem

serrate - (of gill edges): ranging from sawtooth-like to near ragged.

um - one thousandth of a millimeter = micron

REFERENCES (References not given in 1987 key)

1. Arora, David. 1986 Mushrooms Demystified Second Edition. Ten Speed Press, Berkeley.
2. Bessette, Alan E., Bessette, Arleen R., Fischer, David W. 1997. Mushrooms of Northeastern North America. Syracuse University Press.
3. Bessette, Alan E., Bessette, Arleen R., Miller, Orson K. Miller, Hope H. 1995. Mushrooms of North America in Color: A Field Guide to Seldom-Illustrated Fungi. Syracuse University Press.
4. Castellano, M., Jane E. Smith, Thom O'Dell, Efrén Cázares, Susan Nugent. 1999. Handbook to Strategy 1 Fungal Species in the Northwest Forest Plan. General Technical Report PNW-GTR-476. United States Department of Agriculture.
5. Courtecuisse, R., Duhem, B. 1995. Mushrooms and Toadstools of Britain & Europe. Collins Field Guide Harper Collins, London.
6. Farr, D.F., G.F. Bills, G.P. Chamuris & A.Y. Rossman. 1989. Fungi on plants and plant products in the United States. APS Press, St. Paul. 1252 p.
7. Ginns, J. 1986. Compendium of plant disease and decay fungi in Canada 1960-1980. Canad. Dept. Agric. Publ. 1813: 1-416.
8. Miller, Orson K., Linnea Stewart. "The Genus Lentinellus." Mycologia 63: 333-369. 1971.
9. Pegler, D.N. 1983. "The genus Lentinus: a world monograph." Kew Bull. Addit. Ser. X: 1-281. (not used for this key)
10. Petersen, R.H., Hughes, Karen W. A preliminary monograph of Lentinellus (Russulales). Bibliotheca Mycologica Band 198. J. Cramer. Germany 268p.
11. Phillips, Roger. 1991. Mushrooms of North America. Little, Brown, & Co., Boston.
12. Redhead, S.A. 1997. Macrofungi of British Columbia: Requirements for Inventory. Ministry of Forests of British Columbia.
13. Redhead, S.A., James H. Ginns. 1985. "A reappraisal of agaric genera associated with brown rots of wood." Trans. Mycol. Soc. Japan 26: 349-381.
14. Watling, R., Norma M. Gregory. 1990. British Fungus Flora Agarics and Boleti 6 Crepidotaceae, Pleurotaceae and other pleurotoid agarics. Royal Botanic Garden, Edinburgh.

INDEX

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