Observation 3717: Agaricus L.

When: 2007-06-29

Collection location: Grass Lawn Park, Redmond, King Co., Washington, USA [Click for map]

Who: Luke Bayler (Matango)

Specimen available

growing clustered under maple

pileus: diam: 120 mm wide and 45 mm high in mature specimens, 30 mm wide and 13 mm high in buttons; exterior reddening after rubbing

trama: 10 mm thick in mature specimens, 7 mm thick in buttons; slightly bitter taste; interior staining yellow after cutting

lamellae: 50 mm long and 9 mm high in mature specimens, 16 mm long and 3 mm high in buttons; pinkish gills, darkening with age

stipe: 50 mm long, 11 mm wide at apex, 15 mm wide at base in buttons, slightly bulbous-clavate; 75 mm long, 22 mm wide at apex, 24 mm wide at base in mature specimens, curved towards base, slightly bulbous base; in general the stipe is irregularly shaped

[admin – Sat Aug 14 02:00:49 +0000 2010]: Changed location name from ‘Grasslawn Park, King County, WA’ to ‘Grasslawn Park, King Co., Washington, USA’


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Add Comment
RE: Did it get reddish immediately or yellow first?
By: Luke Bayler (Matango)
2007-07-02 12:10:29 CDT (-0500)

It seems to flash yellow, and then slowly turn brown/red. As Arora puts it, “fleetingly lutescent.”

Did it get reddish immediately or yellow first?
By: Nathan Wilson (nathan)
2007-06-29 22:50:42 CDT (-0500)

In Agaricus the staining reaction and the odor are key features. The very common section Xanthodermati, stain yellow and then turn brown which can sometimes be reddish. The unpleasant taste/odor would be consistent with that group. I don’t know of any Agaricus species that have a red staining pileus and yellow staining flesh.