LBM - Little Brown Mushrooms
LBM is a famous acronym to describe the mushrooms that most laypeople never bother to learn... too small and too drab to be noteworthy (and therefore very difficult to tell apart). Although the phrase LBM refers to many more mushrooms than are found on this page, I am extending the definition of brown to also refer to the spore colour. These are the drabbest of the drab, where even on a microscopic level, the spores are not an interesting colour. (To be fair, Bolbitius and Conocybe have some non-brown mushrooms.) Most are saprophytic, but Alnicola is mycorrhizal.
|Also consider some Hypholoma (growing in moss) and Stagnicola (a cross between Hypholoma, Xeromphalina and Phaeocollybia) from dark spored families which may have pale enough spores to be looked for here.|
Key to LBMs: (hygrophanous and dry capped, unless otherwise stated).
Albogymnopilus - white with rusty gills. The true position of this rare mushroom is not known, and may deserve a genus of its own.
Melanotus - sometimes with an off-centre stem so you will also find it on the oyster mushroom page. Pale to dark brown, found on wood or sometimes on carpets and fabric! It may have regular brown or dark purple-brown spores. It is related to (and probably actually is) Deconica (Psilocybe) in the Strophariaceae family, although it does not really resemble it from a human point of view. Dryer cap than Pholiota. Something close to adnate gills, but attachment varies. Tiny mushrooms are hard to get a spore print from, so you may even look for it on the white spored marasmioid page. Very small (<2.5cm). Dry capped and not hygrophanous.
Deconica (Melanotus) horizontalis (textilis) - pale to dark brown, sometimes furry cap and stem. Purple-brown spores. <2cm.
D. (M.) phillipsii - paler with pale brown spores, not furry, found in the wild on dead grasses and sedges. <1cm.
Phaeomarasmius/Flammulaster - scaly LBMs.
Phaeomarasmius erinaceus - Dark brown, dry, very scaly cap, on hardwood, with the typical curved stem of something growing out from the side of a piece of wood and turning upwards. Somewhat adnate gills. <1.5cm. Scalier than Melanotus. Dryer cap than Pholiota. Closely related to Tubaria.
Flammulaster granulosus - also scaly (but not usually as much as Phaeomarasmius) but usually on the ground and therefore with a longer, straighter stem. Somewhat adnate gills. Closely related to Tubaria but more granular. <1.5cm.
F. rhombosporus/muricatus - known from California, are to be looked for as well.
Simocybe - on wood, with an overall pruinose look and white mycelium visible at the base of the stem and white gill edges, but not distinctive and hard to recognize. (Smaller and not viscid like Pholiota, and a different look and feel than Galerina or Tubaria). Cap usually hygrophanous. Gills usually adnexed but variably attached. Very similar to Melanotus, which almost always has a shorter stem. This genus is related to Inocybe.
Tubaria - Well, this is it, the quintessential LBM that David Arora calls the boringest of the boring. I disagree, however, as I always try to find something interesting to say about every mushroom and I generally subscribe to the "if you can't say something nice about something..." theory. In this case, Tubarias are strongly hygrophanous. The colour change as they dry out is quite dramatic (see photo) and can start to happen in a matter of minutes. One of them can be blood red. Traditionally recognized by having slightly decurrent gills, although that's not foolproof. Supposedly dry capped and striate at least when moist. Member of the Crepidotaceae family.
T. furfuracea grp - common anywhere at any time but especially in the winter months. Drying out very pale. Veil very fleeting. Usually <2.5cm.
This variation must be a different species. Not as delicate, darker red colour, veil remnants on cap rim. Similar to T. vinicolor.
T. conspersa - fibrils all over the cap and stem, not as granular as Flammulaster.
I've found another ringed species looking much like Laccaria, but more orange than red.
T. punicea - fleeting veil, on Madrone, beautiful burgundy. Resembles Laccaria. Also up to 5cm.
Bolbitiaceae - delicate LBMs found in grass, manure, rotting debris or wood with an often viscid, striate, non hygrophanous cap. Gills may be free but are sometimes adnexed. They are very much like Psathyrella and the inky caps, but with lighter brown spores. The spores have a kind of a rusty tint to them like Cortinarius, but these are usually paler. This gives these mushrooms cinnamon coloured gills in maturity.
This family has a cellular cap cuticle (the top layer of cells inflated and round) like Agrocybe, Psathyrella, Panaeolus and the Inky Caps. (And the Russulaceae, but their entire fruitbody is cellular). This sometimes gives them a subtle granular look, but it also makes them susceptible to breaking in any direction, not just radially from the cap to the centre. Put a little bit of pressure on the cap by bending it and see if you can get it to easily break like this:
That might indicate a cellular cap cuticle, although any old rotting mushroom is also likely to break easily in any direction.
Bolbitius - usually a viscid, striate capped, yellow LBM, but may have olive colours too, or be less colourful or with an interesting reticulated cap. <4cm.
Conocybe - the "coneheads". Often strongly conical, dry sometimes striate capped, delicate brown or white LBMs, typically hygrophanous. The main Conocybes have no veil, but some have a veil that leaves a ring on the stem. These are sometimes called Pholiotina, and at least some of them are DEADLY POISONOUS containing the same toxin as the deadly Amanitas. (Remember, rings can fall off, so any LBM could potentially be deadly). This genus is little studied in the NW, and there are potentially many different local species being called C. tenera or C. filaris. Conocybe can be told microscopically by the round headed sterile "cystidia" on the gill edges. Pholiotina does not have them. Usually <2.5cm.
Alnicola (Naucoria) - some of our smallest mycorrhizal mushrooms, these, as the Latin translation "alder loving" might suggest, can only be found under hardwoods like alder, or sometimes willow. Dry, non hygrophanous cap, usually fairly flat (unlike Galerina), gills usually adnexed (unlike Tubaria, the two genera with which it is most easily confused). But in practice, very difficult to recognize as there is nothing distinctive about them. Alnicola have warty spores. Usually <2.5cm across. Other Alnicolas under alder can be found in the PNW, but they are little studied. Closely related to Hebeloma.
Galerina - a confusing unrelated group of LBMs, many of these will need new names as our local Galerinas are going to be split into at least 4 different genera, probably corresponding to the current subgenera Galerina, Naucoriopsis, Mycenopsis and Tubariopsis. The Galerina vittiformis group may be the only species to keep the name Galerina. Most of them are probably somewhat related to the Hebeloma family Hymenogastraceae, except for Tubariopsis which may be in the Strophariaceae. This is, of course, another group that has never been comprehensively studied in the PNW and many, many species are suspected to be here and most of the ones that are known to be here are indistinguishable without a scope. They are found on moss, logs, or mossy logs. The caps are usually dry but occasionally viscid, usually hygrophanous, either having a veil or not maybe leaving a ring on the stem and usually adnexed gills in age but sometimes starting out decurrent like Tubaria. Like Pholiotina (Conocybe), those with a ring may be DEADLY POISONOUS with Amatoxins. Beware all LBMs with a ring, and those without because they may have lost their ring. Most Galerinas have warty spores but at least one of the groups has smooth spores.
There are larger species with hemispherical to flat somewhat striate caps, and smaller Mycenoid species with conical, strongly striate caps and pruinose stems (tiny white powdery dots). The latter species are very much like Mycena, as a matter of fact. All usually hygrophanous, most with a pruinose stem apex and often with a dark stem base. In practice, many are almost impossible to tell apart without a microscope and a lot of practice with it.
G. marginata grp. - viscid?, on wood, occasionally ground, veil leaves a ring or not. Cap hemispherical to flat, resembles Kuehneromyces. Larger, 2-6.5cm. DEADLY. Farinaceous. Pruinose stem apex. (/Naucoriopsis)
G. paludosa - convex to flat (then umbonate), in Sphagnum moss, striate when fresh, veil remnants usually banding the long stem. <2.5cm. Not usually pruinose.
G. tibiicystis - similar, no veil remnants,< 2.5cm. Pruinose. Similar to G. pruinatipes.
G. mammillata - conic then flat with prominent umbo, on wood, dark stem, faintly striate, smooth spored, <2.5cm, not usually pruinose.
G. pruinatipes - similar to G. tibiicystis but on mossy logs. <2.5cm
G. camerina (pseudobadipes) - smooth spored, not pruinose, small umbo, mossy logs, <2.5cm
G. semilanceata (heterocystis/
G. vittiformis grp (atkinsoniana) - mycenoid, in moss, much like G. heterocystis but smaller, usually <1cm. Stem does darken.
G. triscopa - also <1cm, darker orange, on wood.
G. nigripes - mycenoid, but not pruinose like the others, and a dark stem bottom. <1cm. On mossy wood.
I'm having trouble picturing a coffee table picture book on Galerina or Tubaria. However, a mostly all-text copy of Smith's 1964 monograph on Galerina is available here.