North American Species of Crepidotus

Subgenus Sphaerula subg. nov.

Sporae globosae vel subglobosae; fibulae adsunt.

Spores globose to subglobose; clamp connections present on the hyphae of the pileus cuticle or the gill trama, or at the base of the basidium.

TYPE SPECIES: Crepidotus applanatus (Pers.) Kummer var. applanatus sensu Josserand.

Key to Sections

1. Fruiting body stipitate	Section *Nyssicolae*
1. Fruiting body sessile or with a pseudostipe	Section *Sphaerula*

Section Nyssicolae (Singer) stat. nov.

Characters given in the key.

TYPE SPECIES: Crepidotus nyssicola (Murr.) Sing.

1. Pileus deeply depressed, white to cremeous	*C. nyssicola*
1. Pileus convex	2
2. Pileus white to watery white	*C. stipitatus*
2. Pileus isabelline or pinkish cinnamon	Ex 3. *Melanotus eccentricus**

*See Excluded Species

Section Sphaerula sec. nov.

Pileus sessilis vel pseudo-stipitem gerens.

Spores globose or subglobose; clamp connections present; pileus sessile or with a pseudostipe.

TYPE SPECIES: Crepidotus applanatus (Fr.) Kummer

Key to Subsections

1. Pileus at first white, but may become darker (grayish or brownish) in age or when wet, glabrous or white-fibrillose	Subsection *Sphaeruli*
1. Pileus or its fibrils colored	2
2. Pileus at first colored, glabrous or white to buff fibrillose	Subsection *Colorantes*
2. Pileus surface white or colored at first, bearing brown fibrils	Subsection *Fulvifibrillosi*

Subsection Sphaeruli

Characters given in the key.

Type species: Crepidotus applanatus (Fr.) Kummer

1. Pleurocystidia present	2
1. Pleurocystidia absent	4
2. Spores 4-5.5 µ in diameter	*C. subapplanatus*
2. Spores 5-7 µ in diameter	3
3. Pileus developing black spots in age	*C. maculans*
3. Pileus not as above	*C. cystidiosus*
4. Spores 4-5.5 µ in diameter	5
4. Spores 5-7 (8) µ in diameter	10
5. Lamellae broad or medium broad	6
5. Lamellae narrow or moderately so	7
6. Pileus 4-8 (10) mm broad, conchate	*C. conchatus*
6. Pileus 8-25 mm broad, reniform to fan-shaped	*C. tahquamenonensis*
7. Pileus tomentose, cuticle bearing a tangled turf; pileocystidia none	*C. harperi*
7. Pileus glabrose to villose to pruinose	8
8. Cheilocystidia 20-40 (50) µ long, non-septate, cylindric, clavate, or ventricose, pileocystidia often present, 25-65 µ long	*C. applanatus* var. *applanatus*
8. Cheilocystidia not as above	9
9. Cheilocystidia septate, at times forked; pileocystidia up to 60-120 µ long	*C. applanatus* var. *phragmocystidiosus*
9. Cheilocystidia non-septate, often forked or contorted; pileocystidia often contorted, forked or branched	*C. applanatus* var. *diversus*
10. Lamellae narrow, close or crowded	*C. applanatus* var. *globigera*
10. Lamellae broad or very broad	11
11. Pileus hygrophanous, conspicuously darkening on drying	12
11. Pileus not as above	13
12. Pileus becoming fulvous or tawny on drying, glabrous	*C. hygrophanus*
12. Pileus becoming "Prout's brown" on drying, pubescent to fibrillose	*C. brunnescens*
13. Pileus typically very small (6 mm or less)	14
13. Pileus typically broader	16
14. Lamellae unusually broad and distant to subdistant	15
14. Lamellae narrow and close	*C. quitensis*
15. Cheilocystidia cylindric, often capitate	*C. latifolius*
15. Cheilocystidia obclavate, or flask-shaped, or at times fusoid	*C. praelatifolius*
16. Pileus 4-12 mm broad, white-frosted villose	*C. avellaneus*
16. Pileus 10-50 (70) mm broad	17
17. Pileus glabrous, with few or no erect hyphae; no pileocystidia	*C. malachius* var. *malachius*
17. Pileus villose or pruinose; either pileocystidia or a hyphal-turf present	18
18. Pileocystidia present; cheilocystidia non-septate	*C. malachius* var. *trichiferus*
18. Pileocystidia none, a turf present; cheilocystidia at times septate	*C. malachius* var. *phragmocystidiosus*

*See Excluded Species

Subsection Colorantes subsec. nov.

Pileus maturus coloratus, glabrosus vel fibrillas albas aut coriaceas gerens.

Pileus colored at maturity, glabrous, or with white or buff fibrils.

TYPE SPECIES: Crepidotus confertus.

1. Spores 4-5 (5.5) µ in diameter	2
1. Spores 5-7 (8) µ in diameter	9
2. Lamellae narrow or moderately so	3
2. Lamellae broad to medium broad	5
3. Pleurocystidia present; pileus buff	*C. angustifolius*
3. Pleurocystidia absent; pileus color not as above	4
4. Cheilocystidia clavate or ventricose	*C. confertus*
4. Cheilocystidia filamentous to cylindric, flexuous	*C. flexuosus*
5. Pileus yellowish or becoming so	6
5. Pileus brownish or tawny at first	7
6. Pileus at first gray, then yellow, finally brownish	*C. obfuscens*
6. Pileus yellowish, unchanging	*C. constans*
7. Pleurocystidia present	*C. sublatifolius*
7. Pleurocystidia absent	8
8. Pileus pale tawny, dull cinnamon or brown	*C. pallidobrunneus*
8. Pileus gray, then yellow, then brown	*C. obfuscens*
9. Pileus deeply sulcate	*C. aquosus*
9. Pileus not sulcate	10
10. Pileus cuticle of 3-6 (8) layers of repent hyphae	*C. cuneiformis*
10. Pileus cuticle not as above	11
11. Cheilocystidia irregularly shaped, flexuous or contorted	12
11. Cheilocystidia regularly shaped, not contorted	13
12. Cheilocystidia 2-8 µ broad, at least some flexuous or sinuous; gills orange buff	*C. sinuosus*
12. Cheilocystidia 7-13 µ broad, strongly contorted (forked, knobbed, branched); gills white or grayish yellow, becoming brownish	*C. contortus*
13. Lamellae narrow or moderately so; pleurocystidia present	14
13. Lamellae broad or medium broad, at least in age, pleurocystidia absent	15
14. Pileus pink, at least when mature	*C. roseus*
14. Pileus tawny	*C. montanus*
15. Pileus varicolored: white with pallid spots and buff tints, margin drab to cinnamon brown	*C. varicolor*
15. Pileus not as above	16
16. Pileus yellowish; cheilocystidia 25-72 µ long; pileocystidia present, cylindric, clavate, at times crooked or coiled	*C. campylus*
16. Pileus ochraceous; cheilocystidia 26-36 µ long; pileocystidia none	*Melanotus psychotriae**

*See Excluded Species

Subsection Fulvifibrillosi subsec. nov.

Pileus coloratus vel albus, hyphas brunneas fortasse incrustatas gerens.

Pileus colored or white, bearing brown, incrusted, or non-incrusted hyphae.

TYPE SPECIES: Crepidotus nephrodes (B. & C.) Sacc.

1. Pleurocystidia present	2
1. Pleurocystidia absent	7
2. Spores smooth; pileus bright orange-tawny	*C. subnidulans*
2. Spores punctate	3
3. Cheilocystidia irregularly branched, forked, or contorted	*C. distortus*
3. Cheilocystidia regular in form	4
4. Lamellae at first white	*C. appalachianensis*
4. Lamellae at first colored	5
5. Lamellae at first pallid-avellaneous	*C. subfibrillosus*
5. Lamellae yellowish or orange at first	6
6. Pleurocystidia 9-15 µ broad, spathulate, clavate, or ventricose	*C. subaureifolius*
6. Pleurocystidia 4-9 µ broad, often with a long, slender neck	*C. aureifolius*
7. Lamellae at first yellow or orange	*C. crocophyllus*
7. Lamellae at first whitish, pallid or grayish	*C. nephrodes*