A key to Russula subsections Foetentinae and Pectinatae

We hope you enjoy this revision of these aromatic Russula species. Anna Bazzicalupo and RBGE's Dr. Stephan Helfer give an introduction to the revision here. The author would welcome comments via the Scottish Fungi comments form. A PDF of this key can be downloaded here.

By Anna Bazzicalupo

I. Fungus usually small (cap 4 - 7 cm), odour faint, fruity or nauseating. Margin strongly tuberculate. Spores elliptic to broadly elliptic up to 8 µm long with low warts and connections (never with wings or distinct ridges)

II. Species midsized to large (cap 5 - 15cm) with strong odour either unpleasant (foetid) or of marzipan, almonds (cherry-laurel); colours often reddish or brown or ochraceous. Spores elliptic to subglobose often larger than 8 µm (except for R. subfoetens), warted or winged (up to 2 µm in R. grata) with ridges or isolated warts

Pectinatae

Foetentina

R. amoenolens

2

R. pectinata

R. insignis

2

5

R. illota (1)

3

4

R. foetens (2)

R. grata (3)

R. fragrantissima (4)

6

R. praetervisa (5)

R. subfoetens (6)

R. subfoetens var. grata (7)

Russula foetens, with a slight tuberculate margin

Russula foetens, with a slight tuberculate margin.

Key to Species

I. Pectinatae

1a. Spores distinctly elongated to ellipsoid, 9 x 6.5 µm with low warts and very few interconnections. Pileipellis with dichotomously branched end-cells; cystidia black in SV with yellow oily inclusions

1b. Spores ellipsoid to subglobose rarely greater than 8 µm

2a. Spores ellipsoid with few low warts and few connections. Pileipellis with many end cells with small papillae. Odour nauseous and fruity

2b. Spores with distinct low warts and interconnections. Pileipellis with finely encrusted end-cells

II. Foetentinae

1a. Spores ellipsoid, broadly ellipsoid to subglobose greater than 8 µm

1b. Spores broadly ellipsoid, rarely subglobose smaller then 8 µm

2a. Spores rarely greater than 9 µm with irregular and obtuse warts and interconnection with some distinct ridges. Dark marginal cystidia, only terminal parts of cystidia blackening in SV. Always with distinct dark (black purplish) edge to gills

2b. Spores often greater than 9 µm and distinct ornamentation

3a. Spores with pronounced ornamentation, with ridged interconnections, and warts sometimes forming wings

3b. Spores with isolated or connected, distinctly pointed warts. Pileipellis a mixture of long thin elements and broader torpedo-shaped cells; cystidia black with SV. Foetid smell and nauseous taste

4a. Spores with winged ornamentation up to 2 µm with ridged interconnection. Cystidia yellow then grey or black in SV. Acrid taste and strong cherry-laurel almond (marzipan) odour

4b. Spores pointed warts up to 1 µm forming ridged interconnections (zebroid). Pileipellis with obtuse or torpedo shaped cells: cystidia slowly grey black in SV. Acrid taste and strong cherry-laurel almond (marzipan) odour

5a. Spore ornamentation of pointed warts, no interconnections

5b. Spores broadly ellipsoid with pointed warts varying from no interconnections to reticulum-like connections. Narrow finger-like elements in pileipellis; cystidia blackening or greying, sometimes with a reddish hue. Nauseous taste and odour

6a. Strong pointed warts. Pileipellis of shortened elements mixed with rather more torpedo-shaped cells; cystidia black with SV. Acrid taste and unpleasant odour

6b. Carpophore as in R. subfoetens, but with mild taste

Foetentinae Species Notes

1. Russula illota Romagn., Bull. Mens. Soc. Linn. Lyon 23: 112 (1954); Romagn., Bull. Mens. Soc. Linn. Lyon 23: 112 (1954); Romagn., Les Russules d'Europe et d’Afrique du Nord, 350 (1967); Bresinsky, Stangl & Einhellinger, Z. Mykol. 46(2): 136; (1980) Bon, Docums Mycol., 8(no.70-71): 13 (1988).

Type: Romagnesi Herb. N° 51-76

Diagnostic notes: Pileus reddish ochraceous. Spore ornamentation with ridges and pronounced warts. A key distinguishing character is the blackening (purple black) of the edge of the gills. Spore size recorded range: 4.7–7.5 × 5.7-8.1 µm, average 6.4 × 5.2 µm.

Ecology: On soil. Woodland associated with deciduous trees or conifers (Legon et al. 2005).

2. Russula foetens (Pers.) Pers., Observ. mycol. (Lipsiae) 1: 102 (1796); Rea, C., Brit. Basidiom., 464 (1922); Craws., Spor. Orn. Russ., 139 (1930); Singer, R., Beihefte zum Botanischen Centralblatt, XLIX (2): 319 (1932); Melz., Atlas Holu., 191 (1945); Romagn., Les Russules d'Europe et d’Afrique du Nord, 332 (1967); Shaffer, Mycol., 64(5): 1009 (1972); Bresinsky, Stangl & Einhellinger, Z. Mykol. 46(2): 135 (1980); Bon, Docums Mycol., 8(no.70-71): 12 (1988).

Type: as reported by Sarnari (1998): Lectotype (obligatory but not designated) t. 292 Buillard 1788 Herb. France (Agaricus piperatus)

Synonyms: Agaricus foetens Pers., Observ. mycol. (Lipsiae) 1: 102 (1796) Basionym: Agaricus foetens Pers. 1796

Diagnostic notes: Pileus reddish ochraceous. No reaction to KOH. Spores large (ca. 8 µm ) with large isolated warts. Smell foetid (with possible hint of benzaldehyde), taste acrid and persistent. Spore size range: 8.1-11.1 × 7.9-10.7 µm, average 9.5 × 9.9 µm.

Ecology: On soil. Old deciduous woodland. Associated with Fagus or Quercus spp. (sometimes with Betula) (Legon et al., 2005).

Taxonomic notes: Britzelmayr drawing identified by Bresinsky: Britz. 485, 18 Augsburg.

3. Russula grata Britz., Ber. Naturhist. Augsburg 9: 239 (1898) [Index Fungorum] Bot. Centralbl. 15-17: 17 (1893) [Legon et al. (2005)]; Bresinsky, Stangl & Einhellinger, Z. Mykol. 46(2): 135 (1980); Bon, Docums Mycol., 8(no.70-71): 13 (1988); Rauschert, Česká Mykol. 43(4): 198 (1989).

Type: Unknown

Synonyms: Russula laurocerasi Melz., Čas. česk. houb. 2: 243 (1920); Shaffer, Mycol., 64(5): 1039 (1972). Russula foetens var. grata (Britz.) Singer, Beih. bot. Zbl., Abt. 2 49(2): 320 (1932). Russula foetens subsp. laurocerasi (Melz.) Jul. Schäff., Z. Pilzk. 17(2): 51 (1933). Russula foetens var. laurocerasi (Melz.) Singer, Annls mycol. 40(1/2): 73 (1942). Russula subfoetens var. grata (Britz.) Romagn., Les Russules d'Europe et d’Afrique du Nord: 340 (1967). Russula grata var. laurocerasi (Melz.) Rauschert, Česká Mykol. 43(4): 198 (1989).

Diagnostic notes: pileus reddish ochraceous. Spore ornamentation with ridges and highly pronounced wings up to 2 µm. Strong smell of benzaldehyde. Spore size range: 7.4-11.1 × 7.5-10.7 µm, average 8.8 × 10 µm.

Ecology: On soil. Mixed deciduous woodland and in old beech woods. Associated with Fagus, Betula and Quercus spp. (Legon et al., 2005).

Taxonomic notes: The interpretation of Russula grata prior to Bresinsky et al. (1980) was according to Singer, who used the name “grata” to describe a variety of R. subfoetens which had a mild taste. Bresinsky et al. decided, based on the drawing of Russula grata and the knowledge (from a note) that the specimen smelled of sweet almonds, that the species described by Melzer in 1920 as R. laurocerasi (which smells of almonds) was synonymous with R. grata described by Britzelmayr in 1898.

Britzelmayr’s drawing identified by Bresinsky: Britz. 510, 92 Teisendorf, feuchte Schlucht, 7.8.1892 als R. grata Britz. 1893 – 520, 120 Gailenberg bei Hindelang, 5.9.1894 als R. grata Britz. 1893.

Sarnari (1998): Neotype, Romagnesi Herb. N°63-95, however, Romagnesi does not mention the neotypification of R. laurocerasi.

4. Russula fragrantissima Romagn., Les Russules d'Europe et d’Afrique du Nord,: 350; Shaffer, Mycol., 64(5): 1044 (1972); Bon, Docums Mycol., 8(no.70-71): 14 (1988)

Type: in Herb. Romagnesi: 52-173

Synonyms: Russula laurocerasi var. fragrantissima (Romagn.) Bon, Docums Mycol. 17(no. 65): 56 (1986)

Diagnostic notes: pileus reddish ochraceous. Spore ornamentation with ridges and wings up to 1µm, but not as pronounced as R. grata. Strong smell of benzaldehyde. Spore size ranged: 7.5-9.9 × 7.7-10.4 µm and averaged 8.5 × 9.5 µm.

Ecology: On soil. Mixed deciduous woodland.

5. Russula praetervisa Sarnari, Monog. del genere Russula in Europa 1: 463 (1998).

Holotype: 97/812, in Herb. IB. (Sarnari, 1998)

Diagnostic notes: Pileus brownish ochraceous. Spores broadly elliptic with interconnections between warts. Spore size recorded ranged: 4.9-7.4 × 6.1-8.6 µm and averaged 6.2 × 7.7 µm.

Ecology: On soil. Mixed deciduous woodland. Associated with Tilia spp., Betula spp. and Fagus (Legon et al. 2005).

Taxonomic notes: Sarnari (1998) bases his decision to separate the European concept of Russula pectinatoides Peck from the North American concept mainly on spore ornamentation. He observed the North American material to be characterised by spores with isolated warts, while the Mediterranean material was different in that it had thin connections between the warts. It should be mentioned, however, that Shaffer (1972) shows connections between the warts in one of the drawings of the spores of Russula pectinatoides from North America. The present study reports one species present in Britain, differing from the North American Russula pectinatoides Peck in bearing both isolated and interconnect warts, sometimes on the same fungus, and calls this R. praetervisa, even though it also has isolated warts.

6. Russula subfoetens var. subfoetens Wm. G. Sm., J. Bot., Lond. 11: 337 (1873); Smith, W.G., Outlines of British Fungology, 253; Rea, C., Brit. Basidiom., 466 (1922); Singer, R., Beihefte zum Botanischen Centralblatt, XLIX (2): 321 (1932); Romagn., Russules d'Europe Afr. Nord, 336 (1967); Bresinsky, Stangl & Einhellinger, Z. Mykol. 46(2): 141; Shaffer, Mycol., 64(5): 1048 (1972); Bon, Docums Mycol., 8(no.70-71): 12 (1988).

Type: as reported by Sarnari (1998): Neotype Romagnesi Herb. n° 55-47

Synonyms: Russula foetens var. subfoetens (W.G. Sm.) Massee, British Fungus-Fl. (London) 3: 70 (1893); Singer, R., Beihefte zum Botanischen Centralblatt, XLIX (2): 311 (1932)

Diagnostic notes: pileus reddish ochraceous. Spores small with small isolated warts. Positive KOH reaction. Smell different, not foetid, but not of benzaldehyde. Spore size ranged: 6.9-8.1 × 5.5-6.9 µm and averaged 7.4 × 6.1 µm.

Ecology: On soil. Old mixed deciduous woodland. Associated with Fagus and Quercus spp. and less with Corylus (Legon et al. 2005).

Taxonomic notes: There is a drawing by Britzelmayr mentioned in Bresinsky et al. (1980) (523, 127 Teisendorf, 31.7.1892) which was called originally R. foetens, and later modified to R. subfoetens, with a note about it having a “burned flour” smell to it. Bresinsky et al. wonder if it should stay with R. foetens, but surely the “burned flour” smell is not “foetid” but more subtle, hence the appropriate species epithet “subfoetens”.

7. Russula subfoetens var. grata (Britzelm.) Romagn., Russules d'Europe Afr. Nord, 340 (1967).

Type: Unknown.

Diagnostic notes: pileus reddish ochraceous. Spores small with small isolated warts. Positive KOH reaction. Smell different, not foetid, but not of benzaldehyde. Spore size ranged: 6.9-8.1 x 5.5-6.9 µm and averaged 7.4 x 6.1 µm.

Taxonomic notes: this combination was made by Romagnesi (?) to describe a fungus that looked like Russula subfoetens but had spore ornamentation as in R. fragrantissima or R. grata. In this study this name refers to a fungus that is a mild-tasting variety of R. subfoetens described in Britain by Watling (i.e. with small spores and isolated warts).

Exluded Species

In this study some taxa that were previously included in the Ingratae are now excluded (sensu auct.). In the cases of Russula farinipes, R. fellea and R. ochroleuca, this exclusion is supported by previous molecular studies (Miller & Buyck, 2002; Eberhardt, 2002); but in the case of R. sororia, it is a new finding. These taxa are discussed below.

Russula fellea and R. ochroleuca (the Fellinae) are removed from the Ingratae. This study suggests, as in other molecular studies (Miller & Buyck, 2002), that Russula farinipes does not belong to the former group of the Fellinae, and is more related to R. pallidospora (Miller & Buyck, 2002). The main morphological character distinguishing Russula farinipes from the rest of the Foetentinae and the Ingratae is a white spore print (as opposed to cream-coloured).

Russula sororia has always been placed in the Foetentinae, and this is the first study in which this species is excluded. Its position is not clear from the molecular analysis, but it is outside the Foetentinae in all the trees. Despite its previous placement in the Foetentinae and Ingratae, it is morphologically distinct. Russula sororia is characterised by a matte pileus and by much paler colours than those of other members of the Foetentinae. Legon et al. (2005) suggest its synonymy with Russula consobrina, a North American and continental Europe species, which was placed in the Fellinae by Romagnesi (1967) and Bon (1989), and in the Citrinae by Einhellinger (1985). The difference between these two taxa according to Romagnesi (1967) is mainly the spore ornamentation, with isolated warts in Russula sororia and with many interconnections in R. consobrina. Unfortunately, Russula sororia has never been sampled for molecular analysis outside this study.

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