Monday, August 8, 2011

Little Brown Mushroom #8 - Super Sized Edition

Megacollybia rodmani and Pluteus cervinus
Two mushrooms with a similar appearance, Megacollybia rodmani on the left, and Pluteus cervinus on the right.  They both have brown caps, white gills (to begin with), white stems, and grow from rotten wood (sometimes buried).  So what are the differences?

Size might seem to be a difference from the photo above, but the described sizes of these two mushrooms completely overlap; I happened to pick an unusually long stemmed M. rodmani, and a very average P. cervinus.  So size isn't the distinguishing feature.
The cap of M. rodmani is radially streaked (lines coming from the center).  The cap of P. cervinus is smooth and glossy, and little bit sticky given the right weather.  But this could be a hard difference to tell in the field without the two mushrooms together for comparison.
Both mushrooms have gills that start out white.  But P. cervinus turns pinkish.  The gills of M. rodmani stay white, but some guides mention that they develop a ragged or uneven edge (this may be hard to see in the picture).

Perhaps the key field feature is the attachment of the gills.
M. rodmani, pictured above, has gills that are attached to the stem.
P. cervinus, pictured above, has gills that are free from the stem.

At home, they can be separated with a spore print.  M. rodmani has a white spore print, while P. cervinus has a pinkish-brown spore print.

Are there other mushrooms these two could be confused with.  Certainly!  Especially if they are not growing directly on a rotten log, but on buried wood.  M. rodmani, could be confused with species of Tricholoma or Collybia, while P. cervinus could be confused with species of Entoloma (and for both, many more I imagine).

Both are edible, but I've never tried either one.  But honestly, I'm not 110 % certain of my identification, maybe 95 - 99% certain.  But I'm pretty cautious, and I really don't need to eat mushrooms to thoroughly enjoy finding, observing, and identifying them (I really enjoy bird watching too, and I hardly ever eat any warblers, etc).