Psathyrella microrhiza

Psathyrella microrhiza (Lasch: Fr.) Konr. & Maubl. 1948 in Encycl. mycol. 14 (Agaricales 1): 123

MycoBank: 304299
Basionym: Agaricus microrhizus Lasch 1828 in Linnaea 3: 426
Original diagnosis:

"468. AGARICUS microrhizus n.
Char. ess. Pileo membranaceo campanulato laevi sicco subrufo, lamellis adnexis angustis e pallido nigrescente-brunneis, stipite sericeo albido breviter radicato.
Descr. br. Insignis specis. Initio totus, praesertim ad stipitem, pilis brevibus, erectis, luteis, deciduis, ad marginem pilei vero, cortina tenui, floccoso-annulata, fugacissima vestitus. Pileus ex ovato-margine inflexo-campanulatus, 3/4 - 1 unc. latus, fragilis, particulis submollibus nitentibus tectus, humidus ochraceo vel rufo-brunneus, siccus pallidus. Lamellae facile secedentes, confertae, tenues, lineares, albo-marginatae, demum nigrescentes, in humido vix liquescentes. Stipes 2 - 2 1/2 unc. longus, 1 - 1 1/2 lin. crassus, sursum subattenuatus, basi incrassatus, radice 1 1/2 - 3 lin. circiter longa, distincta. Insipidus et inodorus. Sporidia atra.
In graminosis pinguibus, ad sepes, gregarius, passim.
Sept. Oct."

Important synonyms:

Agaricus microrhizus Lasch: Fr. 1832 in Syst. mycol. 3 (Index): 30
Drosophila microrhiza (Lasch) Quél. 1896 in Enchir. fung.: 118
Psathyra microrhiza (Lasch) P. Kumm. 1871 in Führ. Pilzk.: 70
Pilosace microrhizus (Lasch) Kuntze 1898 in Revis. gen. pl. 3: 504
Psilocybe microrhiza (Lasch: Fr.) Feltgen 1906 in C. r. Soc. Nat. Luxembourg 16: 232
Psathyrella microrhiza f. pumila Kits van Wav. 1985 in Persoonia, Suppl. 2: 281
Drosophila stellata Romagn. 1952 in Bull. mens. Soc. linn. Lyon 21: 152
Psathyrella stellata (Romagn.) M. M. Moser 1967 in Kl. Krypt.fl. 2b/2, 3. ed.: 215 (inval.)
Psathyrella stellata (H. Romagnesi) H. Romagnesi 1982 in Bull. trimest. Soc. mycol. Fr. 98(1): 21 (inval.)
Psathyrella stellata (Romagn.) Romagn. ex Bon 1983 ("1982") in Doc. mycol. 12(48): 52

Misappl.:
Psathyrella bifrons (Berkeley) A. H. Sm. ss. Kits v. Wav. 1985 in Persoonia Suppl. 2: 69f.

Psathyrella badiovestita P. D. Orton 1960 in Trans. Br. mycol. Soc. 43(2): 368
Psathyrella connata Kits v. Wav. 1976 in Persoonia 8: 363
Psathyrella squamifera P. Karst. 1983 in Meddn. Soc. Fauna Flora Fenn. 10: 60
Psathyrella atomata sbsp. subrosea P. Karst 1879 in Bidr. Känn. Finl. Nat. Folk 32: 524
Psathyrella subrosea P. Karst. 1879 in Medd. Soc. Fauna Flora Fenn. 5: 33
Agaricus semivestitus Berk. & Broome 1861 in Ann. Mag. nat. Hist., Ser. 3 7: 376
Psathyra semivestita (Berk. & Broome) Sacc. 1887 in Syll. fung. 5: 1071
Drosophila semivestita (Berk. & Broome) Quél. 1888 in Fl. mycol. Fr.: 62
Pilosace semivestitus (Berk. & Broome) Kuntze 1898 in Revis. gen. pl. 3: 504
Psathyrella semivestita (Berk. & Broome) A.H. Sm. 1941 in Contr. Univ. Mich. Herb.: 57

Select. descript.: Breitenbach & Kränzlin (1995): 272 (as Psathyrella microrrhiza), Enderle (1998): 71ff. (as P. stellata), Enderle & Zuccherelli (1993): 127f., 136f. (as P. stellata), Fouchier (2002): 36f. (as P. stellata), Galland & Romagnesi (1975): 220 (as cf. Drosophila microrrhiza), Heykoop & Esteve-Raventós (1994): 47ff. (as P. microrrhiza), Kits v. Wav. (1971a): 269ff. (as P. microrrhiza), (1976): 356ff. (as P. bifrons), 363ff. (as P. connata), 401f. (as P. stellata), (1985): 59ff., 67ff. (as P. stellata), 69ff. (as P. bifrons), 72ff. (as P. connata), Krieglsteiner & Gminder (2010): 626, Ludwig (2007): 611ff., Muñoz & Caballero (2012): 51ff., Örstadius & Knudsen (2008): 593 (as P. microrrhiza), Orton (1960): 368 (as P. badiovestita), Romagnesi (1982): 21ff. (as P. stellata), Smith (1941): 57f. (as P. semivestita), (1972): 198f. (als P. squamifera), Tassi (2000): 344ff., 346ff. (as P. cf. stellata)
Select. icons: Breitenbach & Kränzlin (1995): 273 (as Psathyrella microrrhiza), Enderle (1994): after page 72 (as P. stellata), Enderle & Zuccherelli (1993): 127, 136 (as P. stellata), Fouchier (2002): 42 (as P. stellata), Heykoop & al. (2017a): 87 (Fig. 8) (as Psathyrella microrrhiza), Krieglsteiner & Gminder (2010): 627, Ludwig (2007a): 180 (as P. microrrhiza), Montag (2010): 56, Muñoz & Caballero (2012): 50, Tassi (2000): Plate 1 + 2 (as P. cf. stellata)

Macrocharacters:
Pileus (10-) 15-30 (-40) x 5-20 µm, convex to campanulate, old flattening, with central umbo, fresh dark brown to red brown, rapidly brighter brown, dry grey brown, sometimes with pinkish tones, margin often rich in contrast brighter, moist high-striated, later moderately to strongly rugolose. Young with white veil floccs almost to the center, later smooth.
Lamellae close, at first whitish to cream with white edge. Later grey brown to blackish brown, edge without gaps reddish or red underlined, mostly white fimbriate.
Stipe 10-65 (-150) x 1-5 mm, whitish to pale brownish, hardly fibrillose, apex pruinose, base tomentose and often with a 10-20 (-50) mm long pseudorhiza.
Spore print black with a trace of red.

Microcharacters:
Spores (8,7-) 11,2-13,5 (-15) x (5-) 5,5-7,5 (-8) µm, av. (10,1-) 11,4-13,8 x 5,6-6,9 µm, av. Q=1,70-2,46, ellipsoid to minimally ovoid, often very slender, germ pore large and truncat. In water brown, in ammonia reddish brown, in KOH dark red brown to blackish brown, subopaque to opaque.
Basidia 17,4-35,5 (-40) x 8,2-13,5 µm, 4-spored.
Cheilocystidia (16,5-) 20-50 (-65) x 5,5-16,5 µm, mostly very crowded, only sometimes with gaps. Undermixed by mostly rare sphaeropedunculate and clavate marginal cells, 5,5-33 x 5,5-20 µm, sometimes with slightly thickened, yellowish walls. Edge depending on age 20-100 (-300) µm wide yellowish brown, ochre or brown pigmented.
Pleurocystidia (35,5-) 40-80 (-90) x 8,2-15 (-16,5) µm, mostly numerous. Sometimes (sub-) capitate or forked.
Veil cells 20-95 x 3-16,5 (-20) µm, cylindrical to slightly ventricose, slightly branched, often septate, colourless and without deposits.
Clamps present.

Habitat: Grasslands, ruderal, leaf litter in forests, dead wood, wood chips.
Distribution: Austria, Czech Republic, Denmark, Finland, France, Germany, Iceland, Norway, Slovak Republic, Spain, Sweden, Switzerland
Remarks:
Kit v. Wav. (1985) describes a forma pumila, which differs only in small fruiting bodies.
Ludwig (2007) reduced Psathyrella connata Kits v. Wav. to Psathyrella microrhiza f. connata, because apart from merismatic growth, there are no significant differences. At the same time pointed out, that Kits v. Wav. (1985) indicates smaller spores (up to 12,6 x 6,8 µm). This measure, however, fits easily into the concept of Psathyrella microrhiza . Figure in Ludwig (2007a): 181.
Smith (1972) cited from Lasch's original concept of Psathyrella microrhiza "... Pileo primitus luteo-piloso ...", from which he concludes that it must be a fungus with yellow veil and must applied the concept was incorrect. However, Smith does not cite Lasch, but Fries (1838).
According to molecular biological studies notice Vasutová & al. (2008) that between Psathyrella microrhiza (there microrrhiza) and Psathyrellacorrugis (there gracilis) are finding no significant differences, probably here are divergent species concepts based.
Essartier (2004) describes (ad int.) Psathyrella microrhiza var. laeta; a taxon with intermediate characteristics between Psathyrella corrugis (there: gracilis) and Psathyrella microrhiza.
The original spelling "rhiza" (as in "pseudorhiza"!), also sanctioned by Fries (1832), should be maintained (neo-Latin).
Coll. exam.:
(G) Saxony: Kyhna, 05.12.04 (AM473); 08.10.05 (AM640); 26.10.05 (AM674); 04.11.05 (AM688) + (AM723); 13.10.06 (AM826); 12.11.06 (AM878) + (AM881); 14.11.05 (AM711); 10.11.06 (AM877); 14.11.06 (AM896); 15.11.06 (AM897); 19.11.06 (AM902); 17.12.06 (AM939); 03.10.07 (AM1018); 06.10.07 (AM1038); 17.11.07 (AM1101) + (AM1103); 30.10.09 (AM1313); 02.10.10 (AM1437); 22.10.11 (AM1480); 30.10.11 (AM1489); 04.11.11 (AM1493); 23.12.11 (AM1547); 13.10.13 (AM1645); 12.10.13 (AM1646); 25.10.15 (AM1723); 25.10.15 (AM1727); Delitzsch, 10.11.05 (AM693); 02.10.08 (AM1191); 07.10.08 (AM1197) + (AM1198); 14.10.08 (AM1204); 09.11.08 (AM1228); 24.09.10 (AM1440); Bad Düben, 25.09.10 (AM1438) + (AM1439); Brinnis, 28.09.13 (AM1626); - Leipzig, 11.10.16, leg. L. Kreuer (AM1944); 23.10.16, leg. L. Kreuer (AM1946); 23.10.16, leg. L. Kreuer (AM1947); 02.11.16, leg. L. Kreuer (AM1948); -
Sachsen-Anhalt: Landsberg, 01.12.06 (AM922); 14.09.07 (AM1005); - Schleswig-Holstein: Nordfriesland, 24.10.05, leg. T. Pruß (AM678); - Hamburg (all leg. M. Vega): 19.10.07 (AM1056); 28.10.07 (AM1061); 04.11.07 (AM1094) + (AM1095); 24.11.07 (AM1122); 27.11.07 (AM1132); 08.12.07 (AM1124) + (AM1125); 15.12.07 (AM1105); -
Herb. Gent University: (5.079); (3.951); (3.998); (2005/19/11/01); (2005/19/11/03).
Historical documents:

Lasch (1828, Orig.diag.):