Rhodocollybia Singer, Schweiz. Zeit. Pilzk. 17: 71. 1939.

Collybia subgenus Rhodocollybia (Sing.) Halling, Mycologia Mem. 8: 19. 1983.

Collybia section Maculatae Lennox ex Halling, Mycologia Mem. 8: 19. 1983.

Section Maculatae Lennox, Mycotaxon 9: 200. 1979, nom. nud.

Basidiocarps fleshy putrescent, arising from soil or litter; spore deposit pinkish buff to pinkish cream; at least some spores dextrinoid and cyanophilous.

Type species: Rhodocollybia maculata (Alb. & Schw.: Fr.) Kummer.

  Key to Species of Rhodocollybia  

For a French translantion by Roland Labbé, go here

1. Pileipellis hyphae repent and radially oriented; taste mild or not distinctive . . . . 2

2. Spores globose. . . . R. prolixa var. distorta (eastern USA) R. badiialba (western USA, IMAGE ONLY )

2. Spores ellipsoid to lacrymoid . . . . 3

3. Spores (6.2-)7-9(-10.5) x 3.5-4.2(-4.8) µm; stipe clavate . . . . R. butyracea (including f. asema with gray brown colors)

3. Spores 5-7.5 x 3-4.5 µm; stipe equal, sometimes subradicating . . . . 4

4. Cheilocystidia present; lamellar edges laciniate or serrate only with age; stipe subradicating inrotten wood . . . . R. unakensis

4. Cheilocystidia absent; lamellar edges distinctly serrate from the beginning; stipe notsubradicating . . . . R. lentinoides

1. Pileipellis hyphae a tangled trichodermium at first, becoming repent and interwoven with age; taste bitter . . . . 5

5. Spores globose to subglobose (5.6-6.4(-7) x 4.8-5.6 µm) . . . . R. maculata var. maculata

5. Spores ellipsoid to lacrymoid (5.6-7 x 3.5-4.2 µm) . . . . 6

6. Lamellae yellow (stipe sometimes yellow) . . . . R. maculata var. scorzonerea

6. Lamellae whitish, lacking yellow colors . . . R. maculata var. occidentalis

Rhodocollybia butyracea (Bull.: Fr.) Lennox, Mycotaxon 9: 219. 1979. Micro features, Macro image

Agaricus butyraceus Bull.: Fries, Syst. Mycol. 1: 121. 1821.

Collybia butyracea (Bull.: Fr.) Kummer, Führ. Pilzk. 117. 1871.

Pileus 20-45(-50) mm broad, obtusely convex with an incurved margin when young, becoming planoconvex to plane or subumbonate with a decurved margin, occasionally uplifted and eroded at margin with age; surface glabrous, lubricous when young, fresh and moist, hygrophanous, even, translucent striate at the margin when aged or in wet weather, reddish brown to violet brown (bay; 7,8,9,10E8) when young, fading to light brown or cinnamon brown (cinnamon brown; 6D8,7,6) eventually overall; context 5-10(-14) mm thick, white to pale watery gray; taste and odor mild or absent. Lamellae adnexed to nearly free, close or crowded, thin, moderately broad (up to 7 mm), white, developing a slight pinkish cast with age; edges wavy or straight to uneven, rarely pubescent, becoming eroded or laciniate with age. Stipe 30-60(-70) mm long, 4-10 mm broad at the apex, clavate, sometimes pinched at the base, fibrous to brittle; surface moist in wet weather, otherwise dry, striate to sulculate, sometimes whitish fibrillose at the base, buff to pinkish buff (3,4,5A3,2) overall at first, or concolorous with the pileus toward the base and pallid above when young, becoming cinnamon brown with age, whitish at base below substrate level; interior white, pithy when young, soon hollow and spongy.

Spore deposit pale pinkish buff (pinkish buff, pale pinkish buff). Spores (6.2-)7-9(-10.5) x 3.5-4.2(-4.8) µm, lacrymoid to ellipsoid or amygdaliform in profile, obovoid to subellipsoid in face or back view, smooth, with a dextrinoid and cyanophilous endosporium and a hyaline apiculus. Basidia 23.8-37.8 x 6.4-7.8 µm, clavate, four sterigmate, not siderophilous. Pleurocystidia absent. Cheilocystidia inconspicuous, recurved to repent along the edge, clavate cylindric to irregularly lobed or diverticulate, 19-35 µm long. Lamellar trama parallel to interwoven, inamyloid; hyphae 4.2-12 µm in diam, smooth and thin walled. Pileus trama interwoven, inamyloid; hyphae 7-12.6(-21) µm in diam, thin walled, usually smooth, yet some cells lightly but distinctly encrusted. Pileipellis a compact layer of radially oriented, repent hyphae, often encrusted with a brownish pigment, sometimes with a superficial gelatinous matrix; hyphae 2.8-5.6 µm in diam. Stipitipellis a layer of parallel, vertically oriented hyphae; cells 2.8-5.6 µm in diam, smooth, usually thin walled, occasionally thickened to 1.4 µm, giving rise to an inconspicuous vesture of scattered, short-contorted caulocystidia, 2-4.2 µm in diam. Clamp connections present in all tissues.

Guzmán and Dávalos (1979) have reported that Christiansenia tumefaciens Ginns and Sunhede (1978) forms galls on R. butyracea in Mexico.

Habit, habitat, and distribution: Scattered, gregarious or subcespitose among conifer humus and needle litter. Widely distributed from late August to October in forests of Pinus, Tsuga, Abies, and Picea.

Discussion: Rhodocollybia butyracea is encountered commonly in the northeast. The species occurs typically in conifer forests, but may be found in mixed woods on conifer humus. Fruitings are most frequent from late summer into autumn. In California, the gray brown variety, R. butyracea f. asema (Fr.) Antonín & Noordeloos is more commonly encountered.

Rhodocollybia butyracea has been confused with G. dryophilus, but it is easily distinguished from the latter by the pale pink spore deposit, dextrinoid and cyanophilous spore walls, and radially oriented, cylindric hyphae in the pileipellis. However, several other species are more difficult to separate (viz., R. prolixa var. distorta, R. badiialba, R. lentinoides, and R. unakensis). The most outstanding feature of R. badiialba and R. prolixa var. distorta is the globose to subglobose spores which can serve to distinguish those taxa from R. butyracea. Also, these two have a positive (pink) reaction when FeSO4 is applied to fresh lamellae.

The spores of Rhodocollybia unakensis and R. lentinoides are lacrymoid to ellipsoid and shorter (5-7.5 µm) than the spores of R. butyracea. In addition, R. unakensis has a subradicating stipe and occurs on rotten wood, and R. lentinoides has conspicuously serrate lamellae from the beginning and lacks cheilocystidia.

Rhodocollybia prolixa var. distorta (Fr.) Antonín, et al., Mycotaxon 63: 365. 1997. Micro features

Agaricus distortus Fr., Epic. Syst. Mycol. 84. 1838.

Collybia distorta (Fr.) Quélet, Mém. Soc. Émul. Montbéliard, sér. II, 5: 95. 1872.

Collybia siticulosa Banning in Peck, Ann. Rept. N.Y. State Mus. 44: 181. 1890 (1892).

Lentinus microspermus Peck, Bull. Torrey Bot. Club 33: 216. 1906.

Gymnopus microspermus (Pk.) Murrill, N. Amer. Flora 9: 361. 1916.

Pileus 10.5 cm broad, applanate, margin irregularly uplifted; surface glabrous, moist, not hygrophanous, smooth and even at the margin, orange brown (54. br 0; 58. m. Br); context thin, pallid. Lamellae uncinate to sinuate, crowded, white becoming brown and eroded on the edges. Stipe 9 cm long, 1.5-2 mm at the apex, compressed, subradicating, splitting into separate strands at the base; surface light tan.

Spore deposit cream white (dry). Spores 4-5.5 x 4-4.5(-5) µm, globose to subglobose, dextrinoid and cyanophilous. Basidia 19-28 x 5.5-7.5 µm, clavate, not siderophilous, rarely scleroid. Pleurocystidia absent. Cheilocystidia scattered, long and flexuous to cylindric contorted or occasionally lobed, 2.5-4 µm in diam. Lamellar trama parallel, inamyloid; hyphae smooth, thin walled, 3.5-9.5 µm in diam. Pileus trama interwoven, inamyloid; hyphae smooth, thin walled, 5.6-14 µm in diam. Pileipellis a layer of repent, smooth, thin-walled, cylindric hyphae, radially oriented; cells 1.5-5 µm in diam. Stipitipellis a layer of parallel, vertically oriented hyphae, giving rise to few short, contorted caulocystidia, 2.5-4 µm in diam. Clamp connections present in all tissues.

Habit, habitat, and distribution: Solitary to gregarious or cespitose in leaf mold or rotten wood. Occuring during May, September through November. Reported by Coker and Beardslee (1921) from North Carolina.

Discussion: The distinctive feature of Rhodocollybia prolixa var. distorta is its globose spores. Other taxa with this spore shape are R. maculata and R. badiialba. Rhodocollybia maculata is readily separated by an interwoven hyphal arrangement in the pileipellis, paler colors, and a bitter taste. On the other hand, R. badiialba remains difficult to distinguish from R. prolixa var. distorta despite the excellent descriptions of Smith (1941), Hesler (1957), and Lennox (1979). Kühner and Romagnesi (1953) and Moser (1978) state that the lamellae of R. prolixa var. distorta become rosy red in contact with FeSO4. My own collections of R. badiialba from California were nearly black when freshly collected and had the charactristic pink reaction with iron salts. Connecticut and Vermont collections gave a faint rosy tint in about l0 minutes after application of FeSO4. As Smith (1941) pointed out, R. badiialba may be conspecific, but lacks cheilocystidia.

Rhodocollybia unakensis (Murr.) Halling, Mycotaxon 63: 366. 1997. Micro features

Gymnopus unakensis Murr., N. Amer. Fl. 9: 366. 1916.

Collybia unakensis (Murr.) Murr., Mycologia 8: 219. 1916.

Collybia egregia Halling, Mycologia Mem. 8: 24. 1983.

Pileus (8-)20-50 mm broad, conic or obscurely umbonate to narrowly convex when young, becoming broadly campanulate to plane; surface glabrous, lubricous when moist and fresh, violet brown (llF8; bone brown) at first, fading to fawn brown (7E5,4) or greyish red (7B5) on the disc and darker toward the margin; context thin, whitish, sometimes pinkish buff immediately beneath the pileal surface. Odor and taste not distinctive. Lamellae sinuate to emarginate with a slight decurrent tooth, close to crowded, thin, narrow, (2-)3-5 mm broad, pinkish buff (5,6A2; pale pinkish buff), sometimes spotted; edges even and entire at first, becoming slightly eroded with age. Stipe 40-70 mm long, up to 6 mm thick, more or less equal, sometimes slightly larger toward the base, fibrous but somewhat fragile, buried in substrate for part of length, with rhizomorphs at the base; surface whitish above, sordid below, longitudinally striate, otherwise glabrous.

Spores 5.5-7 x 3-4.5 µm, lacrymoid to ellipsoid in profile, obovoid to ellipsoid in face or back view, smooth, dextrinoid and cyanophilous, often with a hyaline or collapsed apiculus. Basidia 21-28(-35) x 5-5.5 µm, clavate, four sterigmate, not siderophilous. Cheilocystidia sometimes conspicuous and abundant, usually clavate, occasionally fusoid and then with an elongated apex, 38.5-49 x 5.5-10.5 µm. Lamellar trama parallel, inamyloid; cells 3.5-10.5 µm in diam, smooth. Pileus trama interwoven inamyloid; cells 3.5-10.5(-17.5) µm in diam, usually smooth but sometimes encrusted with a brown pigment. Pileipellis a distinct layer of repent, radially oriented hyphae; cells 2-7 µm in diam, often encrusted with a spiral or band-like pigment, thin walled. Stipitipellis a layer of vertically oriented, parallel hyphae; cells 1.5-3.5 µm in diam, occasionally finely asperulate or slightly encrusted with faint transverse bands of brown pigment, giving rise as recurved end cells or intercalary branches to short (up to 10 µm) caulocystidia. Clamp connections present in all tissues.

Habit, habitat, and distribution: Gregarious to cespitose on rotten wood. Appearing during summer and autumn in the northeast and northwest.

Discussion: This species was previously identified in North America as Collybia extuberans (Fr.) Quélet (Smith 1944). According to Vilgalys and Miller (1987), C. extuberans is a synonym of C. ocior (Pers.) Vilgalys & Miller and belongs in section Levipedes. Rhodocollybia unakensis produces dextrinoid, cyanophilous spores, and the pileipellis is composed of radially oriented, repent hyphae. Even though a spore deposit color is unknown, the reactivity of the spores to Melzer's and cotton blue suggest that R. unakensis has affinities with other taxa in Rhodocollybia.

Rhodocollybia unakensis may be confused with R. lentinoides (see below), but the lamellae of the former are not conspicuously serrate. Rhodocollybia unakensis also has cheilocystidia, a subradicating stipe, and occurs on rotten wood; R. lentinoides lacks cheilocystidia and fruits on humus.

Rhodocollybia lentinoides (Pk.) Halling, Mycotaxon 63: 365. 1997. Micro features, Macro image

Agaricus (Collybia) lentinoides Peck, Ann. Rept. N.Y. State Mus. 32: 27. 1879 (1880).

Collybia lentinoides (Pk.) Saccardo, Syll. Fung. 9: 32. 1891.

Pileus 20-45 mm broad, convex with an incurved margin when young, becoming pulvinate in age with an indistinct umbo; surface dry to moist, hygrophanous, glabrous, dull, cinnamon (cinnamon, tawny olive, clay color) when young, fading to pinkish buff (pinkish buff) between the disc and the margin with age; context white, up to 4 mm thick at the disc; odor and taste mild. Lamellae adnexed to emarginate seceding, up to 5 mm broad, close, thin, whitish to pale buff (cartridge buff, ivory yellow), not staining; edges distinctly serrate to laciniate throughout development. Stipe 20-60 mm long, 3-6 mm broad at the apex, more or less equal, sometimes slightly enlarged at the apex and base, fibrous to fragile; surface dry, subpruinose to substriate (with a lens), whitish and translucent; interior pithy, becoming hollow; not radicating.

Spores 5.4-7.5 x 3.2-4.4 µm, lacrymoid to subellipsoid in profile, ellipsoid to obovoid in face or back view, smooth, dextrinoid and cyanophilous with a hyaline apiculus. Basidia 21-24.5(-28) x (5.6-)6.2-7 µm, four sterigmate, clavate, not siderophilous. Pleurocystidia and cheilocystidia absent. Lamellar trama parallel to subparallel, inamyloid; cells 2.2-7.5(-14) µm in diam, smooth, thin walled. Pileus trama interwoven, inamyloid; cells 4.8-14 µm in diam, smooth, thin walled. Pileipellis a layer of radially oriented, repent hyphae; cells 2-6.4 µm in diam, occasionally branched, sometimes finely encrusted with a brownish pigment, not appearing gelatinous in KOH. Stipitipellis a layer of parallel, vertically oriented hyphae; cells 3.2-7.5 µm in diam, smooth, cylindric, yellowish in KOH. Clamp connections present in all tissues.

Habit, habitat, and distribution: Gregarious on humus under Picea, or in wooded swamps (Peck 1880). Occurring in June and October. Apparently rare.

Discussion: Although a spore print color is not known for R. lentinoides, the presence of dextrinoid and cyanophilous spores would suggest a colored deposit indicating affinity with others in Rhodocollybia. The texture and stature of the basidiocarps also support this alignment. Peck (1880) placed emphasis on the appearance of the lamellar edge as a means of differentiating his C. lentinoides from C. dryophila. Of a more critical nature, the structure of the pileipellis and the reactivity of the spore wall to Melzer's will easily distinguish between these species. Occasionally the lamellar edges of R. butyracea are laciniate or eroded, especially with age, but R. lentinoides can be differentiated by its more or less equal stipe, smaller spores, and the absence of cheilocystidia.

Rhodocollybia maculata (Alb. & Schw.:Fr.) Singer, Schweiz. Zeit. Pilzk. 17: 71. 1939. Micro features, Macro image

Agaricus maculatus Alb. & Schw.:Fries, Syst. Mycol. 1: 45. 1821.

Collybia maculata (Alb. & Schw.:Fr.) Kummer, Führ. Pilzk. 117. 1871.

Agaricus carnosus Curt., Fl. London 5: 71. 1777.

Gymnopus carnosus (Curt.) Murrill, N. Amer. Flora 9: 358. 1916.

Pileus 40-95(-175) mm broad, obtusely convex with an inrolled margin when young, expanding to planoconvex, sometimes with a low, broad umbo, margin becoming decurved; surface glabrous, dry or moist, not viscid, not hygrophanous, pinkish buff to cinnamon buff (pinkish buff, cinnamon buff; 5A3, 5B5) when young and fresh, somewhat paler with age and developing rufescent, ferruginous or reddish brown (7C-D8; 9D8,7) spots; context 8-15 mm thick, whitish; odor none or pungent and fungoid, taste bitter. Lamellae adnate to adnexed, close to crowded, thin, moderately broad (4-8 mm), whitish to pale cream or pinkish buff (4, 5A3, 2), frequently spotted with age (as in pileus) along the sides and edges; edges uneven to eroded, minutely pubescent (with a lens) when dried. Stipe 50-100(-120) mm long, 8-13 mm thick, more or less equal, but subradicating and tapering below the substrate level, fibrous; surface dry, tomentose to pruinose, more rarely subvelutinous, becoming glabrous, striate sulculate, sometimes twisted, whitish, typically developing rufescent spots (as in pileus and lamellae) with age; interior becoming hollow.

Spore deposit pinkish buff to light ochraceous buff (pinkish buff; 73. p. OY; 70. 1. OY). Spores 5.6-6.4(-7) x 4.8-5.6 µm, globose to subglobose or broadly ovoid, smooth, often with a dextrinoid and cyanophilous endosporium. Basidia 21-34.8 x 6.8-8.4 µm, clavate, four sterigmate, not siderophilous, rarely scleroid. Lamellar trama parallel to interwoven, inamyloid; hyphae 3.5-10.5 µm in diam, smooth, thin walled, rarely with oleiferous contents. Pleurocystidia absent. Cheilocystidia 32.2-58.6 µm long, sometimes collapsed on lamellar edge and then inconspicuous, clavate to cylindric or somewhat diverticulate to irregularly lobed. Pileus trama interwoven, inamyloid; hyphae (3.5-)5.6-9.8(-14) llm in diam, smooth, thin walled. Pileipellis a distinct layer of tangled, cylindric hyphae, forming a trichodermium when young, becoming interwoven and repent with age; cells 2.8-5(-5.6) µm in diam, smooth, thin walled, occasionally subgelatinous. Stipitipellis a layer of parallel, vertically oriented hyphae; cells 2.8-4.9 µm in diam, smooth, thin walled, sometimes giving rise to cylindric or flexuous caulocystidia, 3.5-6.3 µm in diam. Clamp connections present in all tissues.

Habit, habitat, and distribution: Scattered to gregarious from buried wood in coniferous forests or in mixed woods with conifers (Picea, Pinus, Tsuga). Occurring in the northeast from July and August into October.

Discussion: The typical form of Rhodocollybia maculata is not uncommon in the northeast, especially during the latter part of the collecting season. Reliable field characters are the pallid colors, rufescent spots on the basidiocarp, thick context, bitter taste, and a subradicating stipe. Microscopically, the dextrinoid, globose spores and the interwoven elements of the pileipellis easily separate this species from others in the genus.

Several varieties of R. maculata have been described. Smith and Hesler (1943) and Lennox (1979) have provided descriptions and keys for the North American variants. The major distinguishing features for these varieties are differences in spore size and shape, color of the lamellae, odor, and the presence or absence of a rufescence. In addition to the type variety, I have found only two others in the northeast. They are R. maculata var. scorzonerea(Fr.) Lennox and R. maculata var. occidentalis (A. H. Sm.) Lennox. Variety scorzonerea is characterized by yellow lamellae (the stipe is sometimes yellow also) and ellipsoid spores measuring 5.6-7 x 3.5-4.2 µm, while variety occidentalis lacks the yellow colors but has the same ellipsoid spores 5.6-7 x 3.5-4.2 µm (see Micro Features). Both of these varieties have a bitter taste.