Mycetinis alliaceus (Jacq.: Fr.) Earle. 1909. Bull. N.Y. Bot. Gard. 5: 414.

Petersen, Ronald H. & Hughes, Karen W., 2017, An investigation on Mycetinis (Euagarics, Basidiomycota), MycoKeys 24, pp. 1-138 : 5-12

1. Mycetinis alliaceus (Jacq.: Fr.) Earle. 1909. Bull. N.Y. Bot. Gard. 5: 414.

Agaricus alliaceus Basionym. Jacquin. 1762. Enum. Stirp. Vindobonensis: 299. ≡ Agaricus alliaceus Jacq.: Fr. 1821. Syst. Mycol. 1: 140. ≡ Marasmius alliaceus (Jacq.: Fr.) Fr. 1838. Epicr. 383.

Type specimen

(neotype, design. Antonín and Noordeloos 1993: Austria, Steiermark, Wildalpen [N47°39'52", E14°59'11"], Lurghöhe, 12.VII.1981, J. Schreurs 578 (L)

Diagnosis.

1) Basidiomata of moderate size (pileus -40 mm broad; stipe 40-85 × 3-5 mm); 2) cheilocystidia short-stalked, digitate to cigar-shaped; 3) stipe brown-black, lightly vestured upward, often pruinose basally; 4) basidia with heterogeneous (multiguttulate) contents; 5) pileipellis elements subglobose to obpyriform, firm-walled; 6) stipe often pseudorhizal, usually associated with Fagus sylvatica ; 7) dried basidiomata retaining garlic taste; 8) basidiospores broadly ovate to amygdaliform, firm-walled; 9) spore contents heterogeneous, with 1-several inclusions.

Description.

Basidiomata (Fig. 3) of moderate size. Pileus 5-45 mm broad, conical when young becoming truncate-conical to more or less plane with downturned margin, usually deeply sulcate-striate almost to disc, smooth (matt, not glabrous), wrinkled (radially and circumferential) when dried, more or less unicolorous, light brown 6D4-6 (near "sayal brown" 6C3 to "tawny olive" 5C5), often with violaceous tint ("tilleul buff" 7B2 to "vinaceous buff" 9B2), reluctantly bruising in spots to "sorghum brown" 8D5; margin delicately scalloped, sometimes abruptly off-white. Lamellae adnate to adnexed, close to crowded, thin, -2 mm broad, entire (not serrulate), total lamellae 75-135, through lamellae 18-24, white to slightly yellowish 5A-B2 to (dried) "ochraceous buff" 5A5, "light vinaceous fawn" 10B2, bruising to "livid brown" 10D4 or “russet” 7D6; lamellulae in 3-4 ranks. Stipe 40-85 × 3-5 mm, erect, terete or somewhat compressed, especially apically, straight, not insititious, upward often brown 6E4-7 to deep maroon ( “Hay’s russet" 8D7, "Kaiser brown" 7E8), downward darkest brown "clove brown" 6F3, "bone brown" 7F8 to "aniline black" 12F3, lightly vestured above, more heavily so near base (and there with mouse gray to "old gold" 3C6 vesture); base occasionally appearing short-pseudorhizal, disappearing in humus, perhaps reaching buried wood, soil often composed of insect castings. Rhizomorphs apparently within substrate (not extrinsically visible), -24 × 0.8-1 mm diam, now copper-brown, curly, occasionally branched; branches usually small, peg-like. Odor strong of garlic; taste distinct of garlic, sometimes also acrid.

Habitat and phenology.

Antonín & Noordeloos (2010) describe ecology as "Gregarious on decaying stems and twigs of Fagus sylvestris , rarely also on the leaves, also recorded from Carpinus … and coniferous needles …” It can be concluded that the preferred substrate is woody. Known from most of the European Fagus distributional area; Russian Caucasus, western Russia, continental Europe, British Isles and Scandinavia; to this time, appearing absent from North America. Late summer, autumn.

Pileipellis a more or less hymeniform layer of inflated cells (Figs 4, 5) not apparently involved in a slime matrix; cells 30-45(-60) × 12-23 µm (at widest point), stalked (stalk 7-40 × 4-6 µm), conspicuously clamped, firm-walled; inflated portion obpyriform to subglobose, firm-walled, hyaline, smooth to minutely roughened, occasionally misshapen, especially at pileus margin, and/or with apical diverticula ranging from short lobes to subcoralloid structures; contents homogeneous. Pileocystidia apparently absent. Pileus tramal hyphae filamentous, 4-8 µm diam, firm-walled, loosely interwoven, conspicuously clamped, not involved in a slime matrix or gelatinized walls. Lamellar trama loosely interwoven; hyphae 4-25 µm diam, firm-walled, conspicuously clamped, hyaline. Pleurocystidia (Fig. 6 A–D) 36-44 × 9-12 µm, fusiform, usually with submammilate apex, thin-walled, conspicuously clamped; contents homogeneous. Basidioles (Fig. 6 E–H) clavate; basidia 39-43(-54) × 10-14 µm, clavate, 4-sterigmate, clamped; contents granular to granulo-guttulate. Basidiospores (Fig. 7) (7.5-)9.5-11.5 × (4.5-)5.5-6(-9) µm (Q = 1.06-2.20; Qm = 1.51; Lm = 9.86 µm), subglobose, ovate to subtly amygdaliform, firm-walled, hyaline, inamyloid; contents heterogeneous with dark inclusions (PhC); spores copious on lamellar surface; empty spores not collapsing. Cheilocystidia (Figs 8, 9) 45-72 × 7-20 µm (at widest point), stalked (stalk 6-12 × 3-5 µm, obscurely clamped), cylindrical, cigar-shaped, occasionally fusiform or sublageniform, bluntly rounded apically, sometimes producing lobate or digitate outgrowths (perhaps when revived in nature or confined), firm-walled, hyaline; contents homogeneous. Stipe medullary hyphae strictly parallel, 4-7.5 µm diam, thin-walled, hyaline, without slime matrix, obscurely clamped. Stipe cortical hyphae coherent but without discernable slime, 4-8 µm diam, thick-walled (wall -1.0 µm thick), obscurely clamped, pigmented yellow-brown, producing caulocystidia as side branches or hyphal termini. Caulocystidia (Fig. 10) from upper stipe scattered, 10-75 × 7-11 µm, digitate, cylindrical, often with constrictions, arising as side branches of stipe surface hyphae or as surface hyphal termini, arranged perpendicular to stipe surface or repent against it, thick-walled (wall -1.5 µm thick), hyaline, smooth. Caulocystidia from stipe base identical, thickly gregarious, 10-110 × 7-13 µm, perpendicular to stipe surface as a turf.

Commentary.

Antonín and Noordeloos (2010): "Lamellae distant, L = 14-24 (27), l = 1-3, free or narrowly adnexed with decurrent tooth, sometimes attached to a pseudocollarium, rather broad, whitish or grayish, often with brown-red stains when old, with entire or pruinose, sometimes serrulate, concolorous or slightly darker edge." Their photo, however, has a suggestion of many more lamellae. As the description above reports, total lamellae and through lamellae statistics do not agree.

Pleurocystidia are apparently produced by selected basidiomata and not by others. The specimen from Austria produced large numbers of differentiated pleurocystidia, but TFB 4731 does not exhibit mature pleurocystidia. Immature pleurocystidia may be present and common, but they are indistinguishable from basidioles. When basidia are nearing maturity they begin to exhibit the heterogeneous contents typical of the species.

TENN-F-55620 was used by Vasiliauskas et al. (2005) as a representative to AFTOL (GenBank AY781252).

Unlike My. scorodonius , which exhibits common differentiated pileocystidia (modified broom cell-like termini) at the pileus margin, the pileipellis of My. alliaceus extends from pileus margin to center with no differentiation of a second element. The most differentiation observed has been some adventitious apical growths from otherwise typical inflated shapes.

Specimens examined.

Austria, Lower Austria, Waldviertel Forest, vic Dobrasperre, N48°38.477', E15°48.338', 24.IX.2001, coll. RHP, TFB 11451 (TENN59312). France, Rhone-Alpes, Dpt. Isére, Col de Granier, 11.IX.2001, coll. RHP, TFB 11352 (TENN59237). Germany, Thuringia, vic. Muchinsojra, Helbeta, N51°24.131', E10°36.052', 30.VIII.2012, coll RHP, TFB 14161 (TENN67911). Russia, Kras nodar Region, vic. Plukh, slopes of Krasnaya Polya, N43°38.677', E40°26.668', 20.IX.1996, coll RHP, TFB 8960 (TENN55620). Sweden, Halland Co., vic Töto Parish, N56°53'50", E12°48'11.5", coll unknown, TFB 4731 (TENN50328); Västergotland, Partille Parish, Jonsered (15 Km east of Gothenburg), N57°44'50", E12°10'25", 28.IX.1991, coll SA Gordon, RHP, Robert Daun, TFB 4737 (TENN50334).