View A43-1112-1979-eng.pdf

EDIBLE AND POISONOUS MUSHROOMS OF CANADA
pileus on a piece of white paper with the lamellae down, wrapping it carefully
in waxed paper, and laying it flat on the bottom of the basket. A good spore
deposit may be obtained by the time one returns from the collecting trip.
If the spore deposit is white to yellow, the amyloid reaction of the spores
should be determined. This reaction is determined by placing some of the
spores on a glass slide and adding a drop of a solution (Meizer's Reagent)
made up of 1.5 grams potassium iodide, 0.5 grams iodine, 20 grams distilled
water and 20 grams chloral hydrate. If the spores turn gray-blue to blackish
blue they are amyloid and if there is no reaction they are nonamyloid. The
reaction can be observed with the microscope if one is available, or, if not, it
can be seen by simply holding the sHde over white paper. The reaction should
be noted within a few minutes of making the test and it is more reliable if
tested on spores that have first been dried. A few species, particularly in
Lepiota, will give a falsely amyloid or pseudoamyloid reaction and the color
will be reddish brown.
This reaction is of considerable importance in taxonomic work. For
example, the genus Leucopaxillus contains some species that were formerly in
Clitocybe and some that were in Tricholoma. These are beheved to form a
natural group and can be recognized by the amyloid reaction of the spores. In
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Figure 45. Spore print of a mushroom.