Summary:
Chlorophyllum agaricoides looks like an unexpanded Agaricus or Lepiota, but has only rudimentary gills and never opens out. It has a whitish fleshy spore mass that becomes yellowish then pale brown.

Cap:
(1)2-7(10)cm across, and 2.5-10(12)cm high, cap spherical to oval to pear-shaped, broadly conic, or heart-shaped (narrower at top); white becoming buff to tan, ocher or brownish; dry, fibrillose, sometimes developing Lepiota-like scales which give it a shredded appearance; margin typically joined to stem, (Arora)

Flesh:
in cap and stem white when fresh, but in one form staining winy-brown when exposed, (Arora)

Gills:
spore mass like contorted gills, chambered; "at first white and fleshy, then turning yellowish and finally becoming brown to yellow-brown in old age, and sometimes powdery", (Arora), whitish becoming pale brown when mature (Phillips)

Stem:
extending up into spore mass, sometimes entirely internal, "but usually extending slightly below the cap (up to 2cm), usually thickest at base of cap"; white when fresh, but often discoloring like the cap when old; "usually with a mycelial cord at base", (Arora), whitish becoming yellowish (Phillips)

Veil:
not clearly differentiated from cap, (Arora)

Odor:
like cabbage in mature specimens (Schalkwijk-Barendsen)

Taste:
sweet and nutty

Microscopic spores:
spores 6-9(11) x 5-7 microns, elliptic, smooth, with a thick inner wall that has an apical pore; capillitium absent, (Arora), spores 6.5-8 x 5.5-7 microns (Phillips)

Spore deposit:
[print not obtainable, spore mass presumably a shade of brown]

Notes:
It has been found in the Rocky Mountains up to 3000m elevation, and also in cultivated areas. It has been recorded from AB, MB, ON, Ukraine, Algeria, Asia, Australia, New Zealand, (Schalkwijk-Barendsen), and is widely distributed throughout North America (Phillips). It has been found in BC and ID (Paul Kroeger, vouchers at University of British Columbia). The University of Washington has collections from WA and ID and Oregon State University has collections from OR. A collection from Italy was used by (Vellinga(5)).

EDIBILITY

caused hemolytic anemia in a dog, which had eaten a mature fruitbody (DE Desjardin pers. obs. as reported in Vellinga(5)); said to be edible when young (Arora), edible when young and tastes sweet and nutty (Lincoff)

Synonyms and Alternate Names:
Endoptychum agaricoides Czern.
Hydnum himantia Schwein.
Mycoacia himantia (Schwein.) L.W. Mill. & J.S. Boyle