Key to Rhodocybe in South America
This key to Rhodocybe was written by Timothy J. Baroni (SUNY Cortland, Cortland, New York, USA) in Mycologia 84: 411-421. 1992. An earlier paper by C. L. Ovrebo and T. J. Baroni (Mycologia 80: 508-514. 1988) described three new species of Rhodocybe from Costa Rica. Two images of Rhodocybe are accessible from the key: R. mellea and R. incarnata.
Vouchers for all collections are on deposit in the mycological herbaria at the Universidad de Costa Rica (USJ) or Instituto Nacional de Biodiversidad (INB). Duplicates are in the Field Museum (F), SUNY Cortland (CORT), or the New York Botanical Garden (NY).
1. Hymenial pseudocystidia present and filled with brightly colored contents in H2O, KOH, or NH4OH .... 2 [Click here to go down to 2nd no. 1]
2. Basidiomata laterally stipitate or stipe absent (section Crepidotoides) .... 31. Hymenial pseudocystidia absent and therefore brightly colored cellular content absent .... 11 [Click here to go back to 1st no. 1]
3. Pileus lingulate, 9 x 7 mm, pileus and lamellae pale grayish to grayish brown, odor and taste mild, clamp connections absent .... R. crepidotoides Sing.2. Basidiomata centrally stipitate (section Rhodocybe) .... 4
3. Pileus circular becoming dimidiate, conchate or reniform, up to 15 mm broad, pileus and lamellae with grayish colors, odor and taste farinaceous or like cucumber, clamp connections present (from Horak, 1979) (Baroni was unable to locate clamps in the type) .... R. conchata Horak (New Zealand)
4. Basidiospores subglobose or pip-shaped in profile view, averaging less than 6.5 µm in length .... 5
5. Cuboid to rectangular, birefringent cyrstals abundant or scattered throughout the hymenium, basidiomata Mycena-like .... R. naucoria Singer4. Basidiospores ellipsoid or broadly ellipsoid or amygdaliform in profile view, averaging greater than 6.5 µm in length; pileus gray or grayish brown and subcanescent or finely pubescent when young; pileipellis two layered, suprapellis thin, hyaline, composed of frequently collapsed, smooth hyphae, subpellis thick, with brownish heavily incrusted hyphae .... R. caelata (Fr.) Maire
5. Birefringent crystals not present in the hymenium .... 6
6. Basidiomata lignicolous .... 7
7. Basidiomata fleshy, Lactarius-like, lignicolous; pileus up to 30 mm broad, plano-convex to plane, brown to dark reddish brown; pileal context with scattered groups of inflated globose cells .... R. lactariiformis Singer6. Basidiomata terrestrial .... 8
7. Basidiomata Galerina-like; pileus up to 16 mm broad, conic, butterscotch; context lacking scattered groups of inflated globose cells .... R. galerinoides Sing.
8. Pileus pinkish cinnamon or cinnamon buff, lamellae concolorous and decurrent; pileipellis with clusters of erect, inflated and incrusted pileocystidia; subhymenium cellular .... R. caelatoidea Dennis
8. Basidiomata differently colored, pileipellis lacking erect inflated pileocystidia; subhymenium not cellular .... 9
9. Pileus up to 15 mm broad, dark brown, odor of celery; spores strongly pip-shaped .... R. collybioides Sing.
9. Pileus up to 45 mm broad, pale cinnamon or dull honey colored, odor if present not of celery; spores may be slightly, but never strongly pip-shaped .... 10
10. Pileus cinnamon, lubricous, frequently umbilicate; lamellae yellowish tan, very crowded; spores 5-5.5 x (3.5-)4-5 µm .... R. russularia Sing.
10. Pileus dull honey-colored, moist, convex becoming plane; lamellae buff, discoloring yellow where bruised, close; spores 5.5-7(-8) x 4.5-5.5 µm .... R. mellea Baroni & Ovrebo (Costa Rica)
11. Clamp connections present (section Rhodophana) .... 12 [Click here to go to 2nd no. 11]
12. Pileus densely squamulose, cheilocystidia ventricose to lageniform, spores strongly undulate-pustulate .... R. fibulata Pegler (Tanzania)11. Clamp connections absent .... 16 [Click here to go back to 1st no. 11]
12. Pileus not densely squamulose, cheilocystidia typically absent (but see R. eccentrica) typically glabrous or occasionally velvety fibrillose .... 13
13. Basidiomata eccentrically to laterally stipitate and lignicolous .... 14
14. Pileus light buff with pinkish hues, lamellar edges smooth; lamellar trama gelatinized, cheilocystidia clavate or sphaeropedunculate .... R. eccentrica Baroni & Ovrebo (Costa Rica)13. Basidiomata centrally stipitate and terrestrial or lignicolous ..... 15
14. Pileus pallid with pinkish hues (vide Horak, 1979), lamellar edges serrulate; lamellar trama not gelatinized, cheilocystidia absent .... R. albovelutina (Stevenson) Horak (New Zealand)
15. On needles of Podocarpus, basidiomata Mycena-like, pileus to 15 mm broad and conic; lamellae deeply sinuate with a decurrent tooth; spores subglobose and often somewhat angular in profile view, 5-5.5 x 4-5 µm .... R. mycenoides Sing.
15. Lignicolous, pileus to 18 mm broad and convex-umbilicate; lamellae adnate; spores broadly ellipsoid or somewhat amygdaliform, 5.5-7(-8) x 4-5 µm .... R. lignicola Sing.
16. Basidiomata eccentrically or laterally stipitate, or stipe absent (section Claudopodes) .... 17 [Click here to go to 2nd no. 16]
17. Basidiomata very small and laterally stipitate, pileus (1-)3-5 mm broad, white and densely tomentose; hyphae of pileipellis heavily incrusted with hyaline crystals .... R. crystallina Baroni16. Basidiomata centrally stipitate .... 20 [Click here to go back to 1st no. 16]
17. Basidiomata larger, colored grayish or brownish; hyphae of pileipellis not incrusted with hyaline crystals .... 18
18. Stipe absent, basidiomata small, pileus 8-15 mm broad, circular to reniform in outline, ash gray; on bark of living tree .... R. pleurogena Pegler (Tanzania)
18. Stipe present, eccentric, pileus 15-50 mm broad .... 19
19. Pileus sordid yellowish brown, lamellae crowded, stipe tomentose to subtomentose; alpine .... R. claudopus Sing. ex Baroni
19. Pileus dark fuscous at first, fading to dull tan, lamellae crowded, stipe glabrous; tropical rainforest .... R. densifolia Baroni & Ovrebo (Costa Rica)
20. Pileus colored pinkish, reddish, brown, tan, fulvous or with some combination of reddish brown or yellowish brown colors, not grayish or white (section Rubrobrunnea) .... 21 [Click here to go to 2nd no. 20]
21. Spores subglobose, broadly ellipsoid or ellipsoid in profile view (Q less than or equal to 1.4) .... 22 [Click here to go to 2nd no. 21]
22. Hymenial cystidia absent, pileus cinnamon to yellowish brown, lamellae adnate, spores 4-6.5 x 3.5-5 µm .... R. pseudonitellina Dennis
22. Hymenial cystidia present .... 23
23. Both cheilocystidia and pleurocystidia present, variously shaped, at times inconspicuous .... 24 [Click here to go to 2nd no. 23]
24. Spores pip-shaped in profile view; pileus dark brown; odor of celery (the pseudocystidia can be inconspicuous and therefore this taxon is included here, also see section Rhodocybe above) .... R. collybioides Sing.
24. Spores subglobose or broadly ellipsoid in profile view; pileus brick red or cinnamon: odor farinaceous or absent .... 25
25. Pileus cinnamon to pale cinnamon; taste and odor farinaceous; lamellae adnate to adnate-decurrent; cystidia lanceolate to lageniform and arising from the lamellar trama (these pseudocystidia can be inconspicuous and therefore this taxon is included here, also see section above) Rhodocybe. . . . R. russularia Sing.
20. Pileus white or colored pale to dark gray, purplish gray or dark grayish brown (section Decurrentes) .... 29 [Click here to go to 1st no. 20]
21. Spores ellipsoid to amygdaliform in profile view (Q greater than 1.4) .... 28 [Click here to go to 1st no. 21]
23. Either cheilocystidia or pleurocystidia present .... 26 [Click here to go to 1st no. 23]
25. Pileus brick red; taste and odor not farinaceous; lamellae decurrent; cystidia versiform, mostly ventricose-rostrate or lageniform, arising from the hymenial layer .... R. testacea Dennis
26. Cheilocystidia not differentiated; pleurocystidia ventricose or ventricose-rostrate with a rounded to capitate apex; pileus bright ferrugineous or reddish orange .... R. laeta Sing.
26. Cheilocystidia present .... 27
27. Tricholoma-like; pileus subtomentose or matted pubescent, bright red at first, more orangish with age; cheilocystidia mostly cylindric, some narrowly ventricose-rostrate, pileipellis a trichodermium .... R. incarnata Baroni & Halling (Costa Rica)
27. Hygrophorus-like; pileus radially silky-fibrillose, pale orange to grayish orange; cheilocystidia cylindric, subclavate or broadly ventricose-rostrate, frequently septate, pileipellis a cutis .... R. hygrophoroides Baroni & Halling
28. Basidiomata terrestrial; pileus ochraceous cinnamon, infundibuliform, lamellae decurrent and distant; hymenial cystidia lacking .... R. rickii var. rickii Sing.
28. Basidiomata lignicolous; pileus ochraceous cinnamon, convex, lamellae decurrent and distant: hymenial cystidia lacking .... R. rickii var. convexa Sing. (Mexico)
29. Pileus white, pale sordid buff, gray, purplish gray or dark grayish brown; 3% KOH spot-test on pleus surface producing a reddish color reaction and solution; lamellae decurrent, narrow and crowded; hyphae of lamellar trama interwoven .... R. mundula (Lasch) Sing.
29. Pileus variously colored grayish to umbrinous but not producing a reddish color reaction in 3% KOH; lamellae decurrent or not; hyphae of lamellar trama parallel or subparallel .... 30
30. Pileipellis two-layered, with a thick hyaline layer overlying a well developed dark brownish subpellis of heavily incrusted hyphae .... 31 [Click here to go to 2nd no. 30]
31. Pileus dark umbrinous, convex; spores (6.5-)7-9 x 5.5-7 µm, subglobose to broadly ellipsoid and angular in profile view .... R. porcelanica (Dennis) Horak30. Pileipellis a single layer of distinctly incrusted hyphae .... 33 [Click to go to 1st no. 30]
31. Pileus brownish beige, grayish brown, mouse gray, milky coffee or clay buff, typically depressed over disc: spores not angular in profile view .... 32
32. Pileus brownish beige, grayish brown or brown; spores 5.6-7.5 x 4.5-5.6 µm, broadly ellipsoid to ellipsoid in profile view .... R. griseola Baroni & Halling
32. Pileus mouse gray or smoke gray, margin becoming milky coffee or clay buff upon expansion; spores 7-9(-9) x 4.5 µm, ellispoid to amygdaliform in profile view .... R. mairei Baroni (USA)
33. Pileus pale grayish brown, convex-umbonate, "taste and odor rancid or like raw cucumber" (fide Horak, 1979), on soil in dunes among herbs and shrubs .... R. ammophila Horak (Papua New Guinea)
33. Pileus grayish to grayish brown, convex-umbonate or campanulate, becoming plane, taste and odor mild, on ground under woody plants (Austrocedrus chilensis, Nothofagus dombeyi, N. antarctica or Pinus sp.) or on woody plants (bark of Salix humboldtiana or Cycas sp.) .... R. semiarboricola Baroni