Key to Major Groups of Mushrooms  

by Michael Kuo

The key below is the starting point for all the identification keys at this site. If you are new to using identification keys, I won't patronize you by explaining the process in elaborate detail; I am sure you will figure it out quickly. However, if you find early on that you are missing information that appears to be crucial, you may want to read Studying Mushrooms before trying to use the keys.

My keys are "artificial," which means that the groups represented in the keys do not necessarily reflect the groups (orders, families, and genera) used by mycologists to portray natural relationships between the fungi. To see how mycologists currently separate the various families and genera, see the Mushroom Taxonomy page. However, if you are trying to identify a mushroom, such a taxonomical arrangement is not likely to help much, unless you have access to a microscope and, in many cases, a DNA laboratory. For this reason the identification keys at this site are based on features that amateur mushroomers can observe.

1.Mushroom growing on other mushrooms or the decayed remains of other mushrooms.

1.Mushroom not growing on other mushrooms.

2.Mushroom with gills on its underside.

2.Gills absent.

3.Growing shelflike on wood (or, if not, then gills concentric rather than radial); mushroom very tough and leathery, corky, or woody (try tearing it in half); gills tough and hard, sometimes maze-like; cap frequently (but not always) with concentric zones of color.

3.Not completely as above.

4.Gills running down the stem, not platelike and thus not easily separable from the cap and stem (try removing an entire "gill" with your fingers or a sharp object); mushroom usually not growing on wood.

4.Gills not as above; mushroom growing on wood or elsewhere.

5.Mushroom with pores on its underside (they may be very tiny; use a hand lens if unsure).

5.Pores absent.

6.Stem absent--or, if present, lateral.

6.Stem present and central.

7.Flesh in stem tough.

7.Flesh in stem soft.

8.Cap round in outline; pore surface not running down the stem, or only slightly running down the stem; spore print not white.

8.Cap round to irregular in outline; pore surface running down the stem; spore print white.

9.Mushroom with spines or "teeth"--either on the underside of a cap, or hanging from a branched structure, or clumped together in an indistinct mass.

9.Spines or teeth absent.

10.Mushroom covered in some part with a foul-smelling slime; arising from a soft underground "egg"; variously shaped (like a club or stick, like crab claws, like a lantern, like a Wiffle ball, etc.); frequently found in urban settings, but also found in woods.

10.Not as above.

11.Mushroom shaped like a cup, a saucer, a goblet, a standing rabbit ear, a bowl, or a saucer that has split into star-like rays; with or without a stem.

11.Mushroom not shaped as above.

12.Goblet or cup with tiny "eggs" inside; mushroom very small.

12.Eggs absent; mushroom variously sized.

13.Mushroom more or less shaped like a ball, or like a ball raised up on a stem, or like a ball set on a starfish.

13.Not as above.

14.Mushroom with a clearly defined, more or less central stem that is separate from a clearly defined cap.

14.Mushroom without a clearly defined cap and stem.

15.Cap shape convex to centrally depressed or vase-shaped; undersurface smooth, wrinkled, or gill-like; rarely fruiting in spring except in warm coastal areas.

15.Cap shape oval, pointed, lobed, saddle-shaped, irregular, or thimble-like (never vase-shaped or convex); undersurface absent, or hard to see or define; many (but definitely not all) species fruiting in spring.

16.Stem completely hollow, or hollow with cottony fibers inside; cap with pits and ridges, or longitudinally wrinkled, or fairly smooth (never lobed or convoluted); without reddish or reddish brown shades; found in spring.

16.Not completely as above.

17.Most (but not all) species found in spring (in north-temperature regions); cap lobed, convoluted, "brainlike," or irregular, with brownish or reddish brown to reddish shades (never black, white, or gray when fresh).

17.Not completely as above.

18.Found in summer and fall (or spring in warm coastal areas); cap lobed, saddle-shaped, or irregular and whitish, grayish, brownish, or black; stem surface ribbed or "pocketed" in some species.

18.Not completely as above.

19.Mushroom thin-fleshed and vase-shaped or tubular--or vase-shaped and fleshy, with scales on the cap surface or with several caps arising from a shared stem.

19.Not as above.

20.Mushroom jelly-like or semi-gelatinous; formless, brain-like, glob-like, or lobed; usually growing on wood or on plants or other mushrooms.

20.Not completely as above.

21.Mushroom shaped like a branched or unbranched club or stick--or shaped like a coral (or a head of cauliflower); most species growing on the ground but a few growing on wood.

21.Not completely as above.

22.Mushroom growing on wood; shaped more or less like a fan or a kidney; underside smooth or vaguely wrinkled, but without pores or gills--or, mushroom without a clearly defined cap or stem, appearing more or less like a crust or a spreading surface that lacks a mushroom; usually growing on the undersides of downed logs.

22.Not completely as above.

Cite this page as:

Kuo, M. (2007, January). Key to major groups of mushrooms. Retrieved from the MushroomExpert.Com Web site:

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