Directions for Using Keys
Let us suppose that the beginner finds a mushroom and wishes to name it. He has learned its component parts. He has remarked the names of the classes into which mushrooms are divided. How then shall he make use of the Keys? We will imagine that he has found a Cantharellus. The cap is yellow color, so let him turn to the list of fungi described under the section “Yellow and Orange,” and see if it agrees in appearance with anyone of these. (It is necessary before consulting a key to find the color of the spores. This is done by cutting off the cap, and placing it, gills downward, on paper, and leaving it there for two or three hours. Having followed these directions in this case it will have been seen that the spores are white.)
After consulting the list of “Yellow and Orange” he will find that the first one mentioned is Cantharellus cibarius, the Chantarelle. The description resembles that of the mushroom found in every particular.
Now let the beginner go further, and prove the correctness of the name in another way. Turning to the section called “General Helps to the Memory,” on page 68, and reading the names of the different genera under the headings until he comes to the name Cantharellus, he will find it in the table called “Mushrooms with gills running down the stems (decurrent).” This distinction is apparent in the specimen found. Again, let him turn to the list of white-spored Agarics, page 73, and he will find the name of the genus Cantharellus there. Now, as an additional test, let him turn to the key at the end of this work, the key to Hymenomycetes. He must have learned enough by this time to know that his mushroom belongs to this class, namely, the one that has spores produced upon the lower part of the cap, and, also, that it is an Agaric, from its having gills on the under side. Let him begin with Section A, “with cap.” 1. Mushrooms with radiating gills beneath caps (Agarics). The key then follows: 1. Plants fleshy, soon decaying. 2. Turn to number 2. There are two descriptions, juice milky and juice watery; he will choose the second one, which is followed by the number 3. Then follows, stem central or nearly so; this agrees with the plant, and leads to 4. The first line reads “white spores,” which is correct; then comes 5. There are four lines with descriptions, the last one, “no ring and no volva,” is right, which leads to 7. There are here two lines belonging to 7, the second one, “gills in the form of folds, obtuse edge,” is correct, and points to 10. This reads, “Gills decurrent, plant terrestrial, Cantharellus.” The Key gives the name of the genus only. In the list of descriptions an attempt is made to mention some of the commonest species. These directions apply to all the keys alike.