Coprinus (Studies in Coprinus - keys to subsections and species in Coprinus)

Key to the subsections in Coprinus

The subsect. Auricomi contains only one species: C. auricomus
Key to the species in subsection Glabri
Key to the species in subsection Setulosi
Key to the species in subsection Nivei
Key to the species in subsection Narcoticii
Key to the species in subsection Domestici
Key to the species in subsection Micacei
Key to the species in subsection Coprinus
Key to the species in subsection Atramentarii
Key to the species in subsection Alachuani
Key to the species in subsection Lanatuli

KEY TO THE SECTIONS AND SUBSECTIONS - Back to top

1. Pileus without veil, smooth or with setulae and/or setae; section Pseudocoprinus
2. Stipe glabrous; pileus glabrous or with scattered, microscopical, long, brown hairs.
3. Stipe and pileus glabrous; spores with eccentric germ pore; subsect. Glabri J. Lange
3. Stipe glabrous; pileus under microscope with scattered, long brown hairs (> 200 m); spores with central germ pore; subsect. Auricomi Sing. (only one species: C. auricomus)
2. Stipe and pileus with setulae and/or setae; subsect. Setulosi J. Lange
1. Pileus with veil, without setules or setae.
4. Veil mainly consisting of elongate elements; section Coprinus
5. Veil scarce, tightly adhering to surface of pileus and usually difficult to remove; basidiocarps medium to rather large with 4-10 mm wide stipe; pileus white, greyish, grey-brown to ochre brown below veil, if white than pileus with annulus on stipe.
6. Pileus grey or brown; stipe without annulus; veil sparse, only at centre and brown; when veil whitish or silvery grey then spores warty; subsect. Atramentarii (Fr.) Konr. & Maubl.
6. Pileus whitish with cream, ochre or darker brown centre; stipe with annulus on lower half of stipe; veil white; subsect. Coprinus Sing.
5. Veil abundant, loosely attached and easy removable from pileus; basidiocarps very small to small, a few medium-sized; stipe 1-4(-6) mm wide; pileus white to greyish below veil, rare brown; never annulus on stipe.
7. Veil made up of chains of smooth, thin-walled, filamentous to elongate, sometimes ellipsoid or a few almost globose elements with distinct end cells; subsect. Lanatuli J. Lange
7. Veil made up of branched, diverculate, thin- or thickwalled hyphae; if elements in chains with distinct end cells then the walls are thickened and yellow-brown; subsect. Alachuani Sing.
4. Veil at least in part consisting of (sub)globose elements; section Veliformes
8. Fruit bodies medium-sized, somewhat fleshy; stipe 3-10 mm thick; pileus usually brown, never pure white; veil present in form of scattered, granulose floccules or small flocculose scales, often (partly) thick-walled and brown-pigmented under microscope; pileus conical or campanulate, long closed, only tardily expanding, never applanate when old, not grooved, without veil at margin when young.
9. Veil present in scattered, granulose flocks which soon disappear, microscopically existing of a layer of globose, thin-walled cells, slightly colouring pink or lilaceous in KOH or ammonia; subsect. Micacei (Fr.) Uljé & Noordel.
9. Veil breaking up in small, more persistent flocculose scales, microscopically existing of chains of fusiform, ellipsoid to globose, in part usually thick-walled cells not colouring in KOH or ammonia; subsect. Domestici Sing.
8. Fruit bodies very small to small, very thin-fleshed; stipe 0.5-3 mm thick; pileus white to grey; veil mealy-powdery, entirely covering the pileus, at centre often woolly-floccose, white, sometimes pale pinkish brown, yellowish or grey; thin-walled, not pigmented or rarely thick-walled, pale yellow-brown in centre of pileus; pileus expanding to become applanate, usually radially grooved and splitting, when young covered in woolly veil at margin.
10. Elements of veil smooth or with crystals that easily dissolve in HCl; spores without episporium; subsect. Nivei Citerin emend.Uljé & Noordel.
10. Elements of veil with persistent, nipple-shaped warts that do not dissolve in HCl; spores usually with distinct, rarely indistinct or lacking episporium; subsect. Narcotici Uljé & Noordel.

KEY TO THE SPECIES IN SUBSECTION GLABRI - Back to top
(For nomenclature and full descriptions see Uljé & Bas, 1988)

1. Basidiocarps growing on pure dung.
2. Pileus > 10 mm when expanded; length of spores 10--15 µm.
3. Spores heart-shaped with average Q less than 1.4: C. schroeteri P.Karst.
3. Spores ellipsoid with average Q more than 1.4: C. megaspermus P.D.Orton.
2. Pileus < 10 mm when expanded; length of spores < 11 µm: C. miser P.Karst.
1. Basidiocarps not on dung.
4. Average breadth of spores > 7.8 µm; spores on average more than 9 µm broad when rounded triangular.
5. Pileus without lilaceous tinges; spores on average less than 9 µm broad when 5--6 angular; cheilocystidia without oily granules.
6. Average length of spores < 11 µm.
7. Spores heart-shaped in frontal view with rounded angles: C. leiocephalus P.D.Orton
7. Spores sub(globose) in frontal view without angles: C. galericuliformis Watl.
6. Average length of spores > 11 µm.
8. Expanded pileus up to 30 mm broad; spores less than 14 µm broad.
9. Spores 10--14 x 7.5--10 µm, elongate 5--6 angular: C. plicatilis (Curt.: Fr.) Fr.
9. Spores 10--16 x 9--13 µm, rounded triangular: C. schroeteri P.Karst.
8. Expanded pileus small, up to 13(--17) mm; spores 12--17 x 11.5--16 µm: C. hercules Uljé & Bas
5. Pileus lilaceous when young and fresh; spores 10--13 x 9--11 x 6--8 µm, 5--6 angular; pileipellis and cheilocystidia with oily granules: C. lilatinctus Bender & Uljé
4. Average breadth of spores < 7.8 µm; spores rounded triangular: C. kuehneri Uljé & Bas.

KEY TO THE SPECIES IN SUBSECTION SETULOSI - Back to top

1. Spores smooth
2. Basidia 4-spored
3. Spores ellipsoid, ovoid or oblong
4. Pileocystidia with distinctly tapering neck
5. No velar spherocysts on pileipellis
6. Germ pore eccentric (sometimes only slightly)
7. With pleurocystidia
8. On dung
9. Clamps-connections absent: C. congregatus
9. Clamps-connections present: C. ephemerus
8. Not on dung
10. Av. Q of spores c. 1.25: C. eurysporus
10. Av. Q of spores c. 1.60: C. sp. Uljé 877
7. Without pleurocystidia
11. Cheilocystidia predominantly globose, subglobose, ellipsoid, broadly ellipsoid, ovoid or obovoid
12. On dung. Pileus < 8 mm in diameter: C. heterosetulosus
12. Not on dung. Pileus larger
13. Pileocystidia > 100 µm. Sclerocystidia present: C. callinus
(compare also C. sclerocystidiosus)
13. Pileocystidia < 100 µm. Sclerocystidia absent: C. sp. Uljé 1009
11. Cheilocystidia predominantly lageniform
14. Av. Q of spores c. 1.25: C. eurysporus
14. Av. Q of spores c. 1.60: C. impatiens
6. Germ pore central
15. On dung and decaying straw. Base of spores rounded
16. With pleurocystidia. Breadth of spores 5-6 µm. Pileus c. 20 mm: C. stellatus
16. Without pleurocystidia. Breadth of spores 4-5 µm. Pileus < 8 mm: C. pellucidus
15. Not on dung. Base of spores rounded or obconical
17. With cylindrical elements of veil on pileus. Base of spores obconical: C. hiascens
17. Without cylindrical elements of veil on pileus. Base of spores rounded: C. impatiens
5. With velar spherocysts on pileipellis
18. On dung. Pileus brown, < 10 mm: C. heptemerus
18. Not on dung. Pileus orange, somewhat larger
19. Cheilocystidia in general ellipsoid to globose: C. pyrrhanthes
19. Cheilocystidia in general lageniform: C. dilectus
4. Pileocystidia (sub)cylindrical, with apex more or less thickened or not, but not tapering
20. Av. length of spores 10-12 µm
21. No velar spherocysts on pileipellis. Not on dung
22. No cylindrical veil on pileus
23. Cheilocystidia globose: C. plagioporus
(compare C. subpurpureus and C. fallax)
23. Cheilocystidia at least partly lageniform
24. Cheilocystidia mixed, ellipsoid to globose and lageniform. Av. Q of spores < 1.80: C. subimpatiens
24. Cheilocystidia lageniform. Av. Q of spores > > 1.80: C. subdisseminatus
22. Cylindrical veil present on pileus
25. Spores < 6 µm broad. Cheilocystidia lageniform
26. Av. Q of spores c. 1.70: C. heterothrix
26. Av. Q of spores c. 2.00: C. sp. Uljé 952
25. Spores > 6 µm broad. Cheilocystidia ellipsoid to globose: C. velatopruinatus
21. Velar spherocysts present on pileipellis. On dung: C. curtus
20. Av. length of spores < 10 µm or > 12 µm
27. Av. length of spores more than 12 µm
28. Cheilocystidia globose or ellipsoid
29. Pileus brown. Sclerocystidia numerous: C. sclerocystidiosus
(compare C. callinus)
29. Pileus with purple tinges. Sclerocystidia rare: C. subpurpureus
C. plagioporus and C. fallax
28. Cheilocystidia lageniform: C. sp. den Held Jager 1276
27. Av. length of spores less than 10 µm
30. With spherocysts on pileipellis. Pileocystidia up to 200 µm long. Base of spores obconical. Germ pore central: C. disseminatus
30. Without spherocysts on pileus. Cylindrical elements of veil present. Pileocystidia < 120 µm
31. Germ pore eccentric. Cheilocystidia lageniform: C. heterothrix
31. Germ pore central. Cheilocystidia ellipsoid to globose: C. sp. Uljé 926
3. Spores mitriform or angular, not ellipsoid, ovoid or oblong
32. Spores mitriform: C. angulatus
32. Spores hexagonal (more or less 6-angled) in front view: C. marculentus
2. Basidia 2-spored
33. Cheilocystidia globose, subglobose, ellipsoid, broadly ellipsoid, ovoid or obovoid
34. No sclerocystidia. No clamps-connections. Pleurocystidia absent or present
35. Pleurocystidia absent. On dung or decaying straw: C. bisporus
35. Pleurocystidia usually present. On sticks, not on dung: C. bisporiger
34. Sclerocystidia, pleurocystidia and clamp-connections present. On dung: C. sassii
33. Cheilocystidia lageniform
36. Germ pore eccentric. Spores ellipsoid. Av. Q of spores 1.75-1.80: C. amphithallus
36. Germ pore central. Spores broadly cylindrical to ovoid. Av. Q of spores 1.35-1.50: C. singularis
1. Spores warty
37. Basidia 4-spored. Cheilocystidia lageniform. Pleurocystidia absent: C. silvaticus
37. Basidia 2-spored. Cheilocystidia ellipsoid to globose. Pleurocystidia present: C. verrucispermus

KEY TO THE SPECIES IN SUBSECTION NIVEI - Back to top

1. Av. length of spores > 12 µm
2. Basidia 4-spored; pileus white at first
3. Spores 12--19 x 11--15.5 µm; spores ± limoniform; pleurocystidia present: C. niveus
3. Spores 10--15 x 6.5--8.5 µm; spores ± 6-angular (hexagonal); pleurocystidia absent or very sparse: C. cothurnatus
2. Basidia 2-spored; pileus grey or cream-grey, sometimes white at first: C. pachyspermus
1. Av. length of spores < 12 µm
4. Spores oval or ellipsoid, sometimes slightly cylindrical
5. Basidia 2-spored: C. bellulus
5. Basidia 4-spored
6. Cystidia absent: C. cortinatus
6. Cystidia present
7. Both cheilo- en pleurocystidia present
8. Pileus very small, expanded < 6 mm; average length of spores < 9 µm
9. In lawns, terrestrial, not on dung, young pileus white; spores 7--9.5 x 5--6.5 µm: C. idae
9. On dung; pileus grey or white and then breadth of spores < 5 µm
10. Young pileus grey; spores 7.5--9.5 x 5--6 µm: C. poliomallus
10. Young pileus white; spores 6--7.5(--8) x 3.5--4.5(--5) µm: C. pseudocortinatus
8. Pileus larger, 5--25 mm when expanded or av. length of spores > 9 µm
11. Expanded pileus up to 25 mm; av. length of spores < 9 µm; on dung: C. utrifer
11. Expanded pileus 5--12 mm; av. length of spores > 9 µm
12. On grasses. Cheilocystidia 20--45 x 8--13 µm: C. pilosotomentosus
12. On wood. Cheilocystidia 50--80 x 20--35 µm: C. nemoralis
7. Only cheilocystidia present
13. Cheilocystidia utriform: C. candidatus
13. Cheilocystidia (sub)globose or ellipsoid
14. Caulocystidia present, with finger-like diverculations at apex; cheilocystidia (sub)globose to ellipsoid, partly also diverculate: C. ramosocystidiatus
14. Caulocystidia absent, cheilocystidia without diverticulations in apical part: see discussion under C. cortinatus
4. Spores differently shaped
15. Spores with rounded angles (4--5-angular), 8--10.5 x 8--10 µm; pleurocystidia present
16. Ring present: C. ephemeroides
16. Ring absent
17. Cheilocystidia in part lageniform. On dung: C. cordisporus
17. No lageniform cheilocystidia present. On vegetable debris: C. patouillardii
15. Spores differently shaped; breadth of spores < 8 µm or spores limoniform; pleurocystidia present or absent
18. Pleurocystidia present
19. Breadth of spores 5--6 µm, heart- or pear-shaped: C. cardiasporus
19. Breadth of spores 7.5--11.5 µm, limoniform: C. pseudoniveus
18. Pleurocystidia absent
20. Veil white, often cream-coloured or slightly ochraceous at centre of pileus; spores ± 6-angular in frontal view, c. 5--6 µm broad; with two bumps at each side: C. iocularis
20. Veil at centre of pileus dark grey, usually with greenish hue; spores narrowly ovoid or amygdaliform, c. 4--5 µm broad: C. coniophorus

KEY TO THE SPECIES IN SUBSECTION NARCOTICI - Back to top

1. Basidia 2- or 3-spored
2. Basidia 2-spored
3. Base of spores conical; average Q of spores > 1.8; spores breadth 6-7.5 µm: C. cinereofloccosus
3. Base of spores rounded; average Q of spores < 1.8; spore breadth 7.5-8.5 µm: C. saccharomyces
2. Basidia 3-spored: C. trisporus
1. Basidia 4-spored
4. On dung or mixed dung
5. Spores with rounded base; episporium scarce, often seemingly absent, smooth
6. Smell strong, (narcotic); pileus up to 12 mm when expanded; never growing from sclerotia
7. Spores 6-8 x 3-4.5 µm, cylindrical ellipsoid; pileus usually white, sometimes greyish: C. stercoreus
7. Spores 7.5-10 x 4.5-6.5 µm; pileus mouse-grey: C. foetidellus
6. Smell of raw potatoes or absent; pileus up to 20(-25) mm when expanded; usually growing from sclerotia: C. tuberosus
5. Spores with conical base; episporium strongly developed, wrinkled
8. Spores 9-13 x 5-6.5 µm; usually not on pure dung: C. narcoticus
8. Spores 12-17 x 6-9 µm; often on pure dung (horse): C. radicans
4. Not on dung
9. On wood; on moss-covered, horizontal cut surfaces of trunks; smell none or indistinct: C. laanii
9. On rotting plants, compost heaps etc
10. Spores with rounded base
11. Average breadth of spores < 6.5 µm; smell of raw potatoes; usually growing from sclerotia; on compost heaps or mixed dung: C. tuberosus
11. Average breadth of spores > 6.5 µm; smell none or otherwise; never growing from sclerotia; never on dung: C. martinii
10. Spores with conical base
12. Average breadth of spores > 6.5 µm
13. Episporium smooth, not strongly developed (up to c. 1 µm wide); spore base only slightly conical; smell none; never on dung: C. martinii
13. Episporium wrinkled, strongly developed (up to c. 2.5 µm wide); spore base distinctly conical; smell strong 'narcotic'; often on dung: C. radicans
12. Average breadth of spores < 6.5 µm
14. Episporium smooth; smell absent or indistinct; average breadth of spores up to 5.5 µm; never on dung: C. semitalis
14. Episporium wrinkled; smell strongly 'narcotic'; average breadth of spores 5.5 µm and more; sometimes on dung: C. narcoticus

COPRINUS SUBSECTION DOMESTICI - Back to top

Basidiocarps medium-sized, somewhat fleshy, pale ochre to ochre; stipe 3-10 mm wide; veil covering entire pileus when young, breaking up of small, woolly flocks (in C. bipellis in patches), microscopically of chains of cylindrical, ellipsoid, broadly fusiform or (sub)globose, hyalin, thin-walled and in part thick-walled and yellow-brown cells; terminal cells distinct, cylindrical, ellipsoid, ovoid or fusiform; pileus subglobose to ovoid, only tardily expanding to campanulate (subsect. Domestici Sing.).

KEY TO THE SPECIES

1. Spores ellipsoid, up to 16 µm long; germ pore eccentric C. flocculosus
1. Spores cylindric-ellipsoid, up to 12(-13) µm long; germ pore central.
2. Spore length up to 12(-13) µm long C. radians
2. Spore length less than 10(-11) µm.
3. Veil breaking up in patches (like in Amanita) C. bipellis
3. Veil breaking up in small, woolly flocks (up to 2 mm diam.).
4. Spore breadth up to 4.5 µm; pileus 25-40 x 20-30 mm before expanding; usually on and around truncs C. domesticus
4. Spore breadth 4.5-5.5 µm; pileus 20-30 x 15-20 mm before expanding; usually on dead branches C. xanthothrix

COPRINUS SUBSECTION MICACEI - Back to top

Basidiocarps medium-sized, somewhat fleshy, pale ochre, rust or cinnamon; stipe 3-10 mm wide; veil made up of very small, scattered, granular flocks, not covering entire pileus when young, microscopically of (sub)globose, hyalin, thin-walled cells, not in chains; pileus subglobose to ovoid, only tardily expanding to campanulate (subsect. Micacei (Fr.) Uljé & Noordel.).

KEY TO THE SPECIES

1. Stipe smooth, caulocystidia absent; spores ellipsoid or ovoid.
2. Pileus rather pale ochre-brown C. truncorum
2. Pileus usually real ochre-brown, rust C. saccharinus
1. Stipe pruinose, caulocystidia present; spores ovoid or mitriform.
3. Pleurocystidia abundant, oblong; spores ovoid C. pallidissimus
3. Pleurocystidia absent or very scarce and then only near lamellae-edge; spores ovoid or (sub)mitriform.
4. Veil dark pinkish brown; spores ovoid or submitriform C. rufopruinatus
4. Veil pale, whitish, cream or ochre; spores distinctly mitriform C. micaceus

COPRINUS SUBSECTION COPRINUS - Back to top

1. Not on dung; spores c. 9-12.5 x 7-9 µm: C. comatus
1. On dung.
2. Spores c. 17-26 x 10-15 µm: C. sterquilinus
2. Spores c. 7-9 x 5.5-6.5 µm: C. spadiceisporus (C. spadiceisporus, Van De Bogart in Mycotaxon 4: 245. 1976. One European found from Italy, Uljé et al. in Persoonia 16: 537. 1998).

COPRINUS SUBSECTION ATRAMENTARII - Back to top

Pileus medium-sized, 30-80 x 20-60 mm, ochre-brown, grey-brown or grey, squamulose only at centre, often seemingly smooth. Growing fasciculate, on wood, trunks or wood-chips. Spores < 10 µm long when smooth, if larger then spores warty (subsect. Atramentarii (Fr.) Konr. & Maubl.).

1. Pileus c. 20-30 mm high, ochraceous, almost smooth; spore breadth 4.5-5.2 µm: C. acuminatus
1. Pileus usually larger, orange-brown, grey-brown or grey; spore breadth 5-6 µm
2. Pileus grey-brown or grey, veil scarce, adpressed, only at centre: C. atramentarius
2. Pileus orange-brown, veil more abundant, squamulose, often with reflexed tips: C. romagnesianus

COPRINUS SUBSECTION ALACHUANI - Back to top

Basidiocarps very small to medium-sized; expanded pileus 6-60 mm. Pileus with veil made up of weakly to strongly diverticulate, and then often thick-walled elements. Stipe smooth, but in most cases covered with very small velar flocks, especially at base (subsect. Alachuani Sing.).

1. Spores smooth, without ornamentation.
2. Basidia 2-spored; spores amygdaloid and truncate: C. piepenbroekii
2. Basidia 4-spored; if spores amygdaloid then never truncate.
3. Average spore length > 10 µm; on dung or soil
(if not on dung or soil step 20).
4. Elements of veil thick-walled, with ascending terminal elements: C. vermiculifer
4. Elements of veil thin-walled; walls < 0.5 µm thick.
5. Breadth of spores < 10 µm.
6. On dung; small species; veil hairy.
7. Pileus white when young; average spore length > 11 µm: C. xenobius
7. Pileus yellow when young; average spore length < 11 µm: C. luteocephalus
6. Not on dung; medium species; veil in patches: C. stanglianus
5. Breadth of spores > 10 µm.
8. On dung, growing on sclerotia: C. sclerotiorum
8. On soil, not on sclerotia: C. picaceus
3. Average spore length < 10 µm.
9. On dung; spores cylindrical ovoid, rounded rectangular: C. filamentifer
9. Not on dung; spores otherwise shaped.
10. Average spore length < 6 µm if veil thin-walled, < 6.5 µm if veil thick-walled.
11. Veil thick-walled; spores globose: C. herinkii
11. Veil thin-walled; spores the shape of a maize-kernel: C. argenteus
10. Average spore length > 6 µm if veil thin-walled, > 6.5 µm if veil thick-walled.
12. Elements of veil thin-walled; walls < 0.5 µm thick.
13. Large species; pileus 50-100 mm when expanded; base of stipe with dark red-brown rhizomorphs: C. strossmayeri
13. Smaller species; pileus 5-40 mm when expanded; no rhizomorphs at base of stipe.
14. Spores rounded quadrangular, with apical papilla: C. episcopalis
14. Spores subglobose to ellipsoid or ovoid, without apical papilla.
15. Terrestrial, on burned or bare soil, or in lawns.
16. Average Q of spores > 1.25.
17. Pleurocystidia up to 55 µm in length with Q c. 2: C. fluvialis
17. Pleurocystidia becoming longer with Q 2.5 and more: C. urticicola var. urticicola
16. Average Q of spores < 1.25.
18. Usually on burned places; expanded pileus 15-30 mm wide: C. gonophyllus
18. In lawns, often on bare soil; expanded pileus 8-15 mm wide: C. epichloeus
15. Not terrestrial, not on soil.
19. Average Q of spores < 1.2.
20. Stipe 2-6 mm wide; on straw, coconut mattings, rotting textiles and straw containing materials like ceilings in old buildings etc., in Europe usually indoors: C. kimurae
20. Stipe 0.5-2 mm wide; on Phragmites, Juncus, and the like, outdoors: C. kubickae
19. Average Q of spores > 1.2.
21. Average Q of spores > 1.55; expanded pileus 10-20 mm wide; spores dark brown: C. goudensis
21. Average Q of spores < 1.55; expanded pileus 6-15 mm wide; spores pale to medium brown.
22. Veil of young pileus white, at centre sometimes pale ochraceous; usually on grasses, but also on other vegetable refuse, sometimes on wood: C. urticicola var. urticicola
22. Veil of young pileus dark grey at centre; on dead branches of willow: C. urticicola var. salicicola
12. Elements of veil thick-walled; walls > 0.5 µm thick in places.
23. Veil mixed with long, brown, thick-walled hairs: C. spilosporus
23. No long, brown, thick-walled hairs present.
24. Walls of velar elements up to 1.5(-2) µm thick in places.
25. Spores short ovoid or subglobose, lentiform: C. phaeosporus
25. Spores broadly ellipsoid, ovoid or slightly rhomboid; not distinctly lentiform.
26. Pleurocystidia 20-50 µm wide: C. xantholepis
26. Pleurocystidia 10-30 µm wide.
27. Veil on pileus white or ochre-brown; excrescences (micr.) often tapering with pointed apex: C. pseudofriesii
27. Veil on pileus dark brown, sepia; excrescences (micr.) often cylindrical with rounded apex: C. tigrinellus
24. Walls of velar elements over 2 µm thick in places: C. friesii
1. Spores warty.
28. Spores amygdaloid: C. echinosporus
28. Spores ellipsoid, ovoid.
29. Basidia 4-spored: C. phlyctidosporus
29. Basidia 2-spored: C. rugosobisporus

KEY TO THE SPECIES IN SUBSECTION LANATULI - Back to top

1. Spores with rounded-conical nodules: C. calosporus
1. Spores smooth.
2. Basidia 2-spored.
3. On dung; veil with some ellipsoid or subglobose elements; average spore breadth < 7.8 µm: C. bicornis
3. On compost or saw-dust; veil without ellipsoid or subglobose elements; average spore breadth > 7.8 µm: C. scobicola
2. Basidia 4-spored.
4. Growing on Ammophila arenaria in yellow outer dunes: C. ammophilae
4. Habitat otherwise.
5. Veil of centre of pileus thick-walled, wall up to 1 µm thick: C. pachydermus
5. Veil of centre of pileus thin-walled, wall < 0.5 µm thick.
6. Veil cream, ochre, yellow, orange or orange-red.
7. Pileus with beautiful rust-coloured or orange-red veil, visible at least at base of stipe, soon slimy: C. erythrocephalus
7. Veil cream, yellowish or ochre, not slimy.
8. Veil cream or pale ochre; spores very broadly fusiform, av. Q < 1.5; on wood, often in wounds of trees; terminal elements of veil up to c. 40 µm wide, not yellowish encrusted: C. spelaiophilus
8. Veil distinctly yellowish or ochre; spores ellipsoid to ovoid, av. Q > 1.5; on clayey soil, mud or wood-chips; terminal elements of veil up to c. 20(--25) µm wide, strongly yellowish encrusted: C. ochraceolanatus
6. Veil white, (silvery) grey or grey-brown.
9. Average spore length < 9.2 µm.
10. Average spore breadth > 5.8 µm.
11. Medium species; spores with av. Q < 1.3; not on dung; veil with elements of one kind: sausage-shaped in chains: C. jonesii
11. Small species; spores with av. Q > 1.3; on dung; veil with two kinds of elements: sausage-shaped and diverticulate: C. candidolanatus
10. Average spore breadth < 5.8 µm.
12. On dung or mixed dung; spores with av. Q > 1.6; spores ellipsoid, tending to cylindrical: C. pseudoradiatus
12. On wood-chips, soil mixed with pieces of wood or vegetable refuse; spores with av. Q < 1.6; spores ellipsoid, tending to rhomboid: C. geesterani
9. Average spore length > 9.2 µm.
13. Average spore length < 10.8 µm.
14. Veil whitish or greyish, hairy-floccose; spores ovoid or ellipsoid; on dung, mixed dung or compostheaps.
15. Veil with one kind of elements, sausage-shaped in chaines; pileus up to 30 mm when expanded; number of lamellae > 35; spores 8.4--11.8 x 5.8--7.8 µm: C. cinereus
15. Veil with two kinds of elements; pileus up to 12 mm when expanded; number of lamellae < 30; spores 7.3--10.7 x 4.8--7.2 µm: C. candidolanatus
14. Veil whitish, cream or pale ochre, in small flocks; spores very broadly fusiform; in wounds of - often living - trees or on stumps: C. spelaiophilus
13. Average spore length > 10.8 µm.
16. Average spore breadth > 8.2 µm: C. macrocephalus
16. Average spore breadth < 8.2 µm.
17. On dung or dung mixed with straw or hay; average spore breadth > 7.8 µm; spores ellipsoid, tending to cylindrical: C. radiatus
17. On soil, often mixed with rotten pieces of wood, wood-chips, compostheaps or vegetable refuse; average spore breadth < 7.8 µm; spores ellipsoid.
18. Veil on pileus thin, cobwebby, looking silky; average spore breadth < 6.7 µm: C. krieglsteineri
18. Veil on pileus abundant, hairy fibrillose; average spore breadth > 6.7 µm.
19. Stipe very fragile, bending down before pileus expands; exclusively in lawns; stipe wall < 250 µm thick: C. lagopus var. vacillans
19. Stipe rather firm, upright; usually on wood-chips and vegetable-refuse; less frequent in lawns; stipe wall up to 450 µm thick: C. lagopus var. lagopus