Subgenus Leptonia

Subgenus Leptonia is characterized by a collybioid or omphalioid, rarely mycenoid or tricholomatoid habit The core of this group in our regions is formed by the species of sect. Cyanula: small mushrooms which grow in field and meadows, often with a blue or steelgrey, more or less polishes stipe. Leptonia is divided in four sections which can be distinguished as follows:

• with clamps
  • habit collybioïd or tricholomatoïd; stipe often fibrous to squamulose; pileipellis a cutis with transitions to a trichoderm, of radially arranged, septate hyphae with intracellular and often also incrusting pigment. cheilocystidia, if present, basidioliform or irregular, not much larger than basidia.
    • section Leptonia
  • Habit collybioïd or omphalioïd; pileipellis a transition between a cutis and a trichoderm, made up of strongly inflated elements with intracellular pigment; stipe usually adpressed fibrillose to glabrous; cheilocystia, if present, often large, lageniform to fusiform and much longer than basidia,
    • section Griseorubida

• Without clamps
  • Cheilocystidia, if present, clavate to cylindrical, about the same size as basidia
    • section Cyanula
  • Cheilocystidia more or less lageniform, much larger than basidia
    • section Rhamphocystotae

Sectie Leptonia

Habit collybioid or tricholomatoid; pileus woolly to squamulose, pileipellis a cutis of septate hyphae with intracellular and often also incrusting pigment. Species in this sections have a pileipellis of long, septated hyphae, which ascend and form small trichoderm-like squamules on the cap surface. Pigment mainly intracellular, but sometimes accompanied by incrusting pigment. Part of the species grow on decaying wood in forest, other can be found in grassland.

Species: E. euchroum (Pers.: Fr.) Donk; E. dichroum (Pers.: Fr.) Kumm.; E. tjallingiorum Noordel.; E. alnetorum Monthoux & Rollin; E. austriacum Courtecuisse; E. allochroum Noordel.; E. violaceozonatum Noordel. & Liiv; E. wynnei (Berk. & Br.) Sacc.; E. callichroum Horak & Noordel.; E. lampropus (Fr.: Fr.) Hesler; E. placidum (Fr.: Fr.) Noordel.; E. coelestinum (Fr.) Hesler; E. lepidissimum (Svrcek) Noordel.; E. juniperinum Barkman & Noordel.; E. beyeri Noordel. & Wölfel; E. insidiosum Noordel.; E. cedretorum (Romagn. & Riousset) Noordel.

Sectie Griseorubida

This section consists of two groups:

• Section Griseorubida with spores more than 10 µm long.
• Section Parvisporae with spores shorter than 10 µm.

Species: E. indutoides (P.D.Orton) Noordel. with var. indutoides, var. griseorubidum (Kühn. ex Noordel.) Noordel., Wölfel & A.Hauskn. en var. pleurocystidiatum Noordel., Wölfel & A.Hauskn.; E. cocles (Fr.) Noordel.; E. calaminare Noordel.; E. griseoxanthopus Courtecuisse; E. farinasprellum Arnolds; E. politoflavipes Noordel. & Liiv; E. sordidolamellatum Noordel. & Enderle; E. olivaceotinctum Noordel.; E. weholtii Noordel.

Section Cyanula

Small mushrooms, often with striking colours; in grasslands.
A striking character in this group of Leptonia in particular, is the occurrence of brilliant granules, often in large numbers in the trama of pileus and lamellae. These granules often hamper good observation of the tramal structure. On the next micro photograph of the pileipellis and underlaying pileitrama in Entoloma leochromus this phenomenon is good visible. Note also the structure of the pileipellis: a typical example of a transition between a cutis and a trichoderm with intracellular pigment.

For the sake of convenience, a number of stirps are distinguished which contain closely related or similar species:

• Stirps Serrulatum. Lamella edge fringed, dark blue to black, strongly contrasting with the sides of the lamellae

  Species: E. serrulatum (Fr.: Fr.) Hesler; E. caesiocinctum (Kühner) Noordel.; E. querquedula (Romagn.) Noordel.; E. carneogriseum (Berk. & Br.) Noordel.; E. linkii (Fr.: Fr.) Noordel.; E. callirhodon A.Hauskn. & Noordel.

• Stirps Griseoviridulum. Stipe blue-green, fibrillose; lamella edge sterile, not coloured

  Species: E. griseoviridulum Courtecuisse

• Stirps Chalybaeum. Pileus and stipe blue to violaceous; lamellae blue when young, later sordid pink.

  Species: E. chalybaeum (Fr.: Fr.) Noordel. met var. chalybaeum en var. lazulinum (Fr.) Noordel.; E. cruentatum (Quél.) Noordel.; E. cyaneoviridescens (P.D.Orton) Noordel.

• Stirps Cyanulum. Pileus and stipe blue; pileus translucently striate almost to centre, smooth, except for the finely squamulose centre; lamella edge concolrous with sides, sterile or fertile

  Species: E. cyanulum (Lasch: Fr.) Noordel.; E. caesiellum Noordel. & Wölfel.; E. pseudocoelestinum Arnolds

• Stirps Corvinum. Pileus and stipe blue to violaceous; pileus usually not translucently striate entirely tomentose to squamulose; lamellae white then pink with concolorous edge. Stipe fibrillose or polished, never squamulose

  Species: E. corvinum (Kühner) Noordel.; E. mougeotii (Fr.) Hesler; E. viiduense Noordel. & Liiv; E. caeruleum (P.D.Orton) Noordel.; E. nigroviolaceum (P.D.Orton) Hesler; E. aethiops (Scop.) Stev.; E. melanochroum Noordel.; E. atrocoeruleum Noordel.

• Stirps Klofacianum. Pileus and stipe blue to grey-violaceous; spores small, isodiametrical, sometimes almost cuboid.

  Species: E. klofacianum Noordel., Wölfel & A.Hauskn.

• Stirps Incanum. Stipe, and often also pileus with yellow to oliveaceous-green colour; context strongly discoloring blue-green when bruised

  Species: E. incanum (Fr.: Fr.) Hesler

• Stirps Roseum. Pileus, and often also stipe, pini; pileus translucently striate; stipe smooth, polished.

  Species: E. roseum (Longyear) Hesler; E. catalaunicum (Sing.) Noordel.; E. ianthinum (Romagn. & Favre) Noordel.

• Stirps Ursulae. Pileus with blue squamules on pink background; lamellae edge violaceous-pink; stipe blue with fine fibrillose covering, glabrescent with age and appearing almost polished.

  Species: E. ursulae Noordel., Wölfel & A.Hauskn.

• Stirps Roseotinctae. Pileus greyish pink, not translucently striate; stipe grey, smooth, polished.

  Species: E. roseotinctum Noordel. & Liiv

• Stirps Asprellum. Pileus yellow-brown, brown, red-brown, or grey-brown, without blue or violaceous tinges, distinctly translucently striate; stipe blue, violaceous or steel-grey, polished

  Species: E. asprellum (Fr.: Fr.) Fayod; E. lividocyanulum Noordel.; E. huijsmanii Noordel.; E. lepiotosme (Romagn.) Noordel.; E. allospermum Noordel.; E. mutabilipes Noordel. & Liiv; E. sodale Noordel.; E. poliopus (Romagn.) Noordel. met var. poliopus, var. discolor Noordel. en var. parvisporigerum Noordel.; E. glaucobasis Noordel.; E. porphyrogriseum Noordel.

• Stirps Anatinum. Pileus brown, grey, red-brown, blackish brown, without blue or violaceous tinges, not or indistinctly translucently striate; stipe blue, violaceous or steel-grey, fibrillose to squamulose

  Species: E. anatinum (Lasch: Fr.) Donk; E. scabrosum (Fr.) Noordel.; E. griseocyaneum (Fr.: Fr.) Kumm.; E. viaregale Noordel.; E. coeruleoflocculosum Noordel.

• Stirps Porphyrofibrillum. Pielus and stipe with porphyraceous colour; stipe fibrilose, not polished.

  Species: E. porphyrofibrillum Noordel.

• Stirps Exile. Pileus pallied, yellow-grey to almost white, with a contrasting dark spot at centre glabrous, except for the finely squamulose centre; lamellae white then pale pink; stipe blue-grey to steelgrey, sometimes with greenish-glaucous tinge, polished.

  Species: E. exile (Fr.: Fr.) Noordel. met var. exile en var. fertile Noordel., Wölfel & A.Hauskn.; E. chloropolium (Fr.) Mos.

• Stirps Formosum. Pileus yellow, orange or vivid coppar brown; stipe polished.

  Species: E. formosum (Fr.: Fr.) Noordel.; E. xanthochroum (P.D.Orton) Noordel.; E. sphagnorum (Romagn. & Favre) Noordel.

• Stirps Rufocarneum. Pileus red, not translucently striate; stipe red, polished; cheilocystidia absent.

  Species: E. rufocarneum (Berk.) Noordel.

• Stirps Queletii. Pielus ochre, when young often with distinct violaceous tinge; cheilocystidia present.

  Species: E. queletii (Boud.) Noordel.; E. kervernii (Guern.) Mos.

• Stirps Sarcitulum. Pileus and stipe sordid yellow to yellow-brown or yellow-grey, never as brightly coloured as in stirps Formosum, pileus often weakly hygrophanous and translucently striate; stipe polished.

  Species: E. longistriatum (Peck) Noordel. met var. longistriatum, var. microsporum (Noordel.) Noordel. en var. sarcitulum (P.D.Orton) Noordel.; E. atromarginatum (Romagn. & Favre) Zschieschang; E. ochromicaceum Noordel. & Liiv

• Stirps Leochromus. Pielus and stipe yellowish grey to greyish brown; pileus entirely finely granulose to minutely squamulose, not translucently striate.

  Species: E. leochromus Noordel. & Liiv

• Stirps Turci. Pileus and stipe dull brown, red-brown or grey-brown, not hygrophanous not or weakly translucently striate, finely tomentose or squamulose; stipe concolorous or paler, polished or with scattered longitudinal fibrils .

  Species: E. turci (Bres.) Mos.; E. pseudoturci Noordel.

• Stirps Scabropelle. Pileus squamulose to squarrose; stipe strongly fibrillose striate ; cheilocystidia absent.

  Species: E. scabropellis Noordel.

Section Rhamphocystotae

Similar to sect. Cyanula except for the large, protruding, lageniform cheilocystidia

Species: E. rhynchocystidiatum Noordel. & Liiv; E. uranochroum Noordel. & Hauskn.