The method of deciding the character of mushrooms by their odor and flavor is not to be relied upon. Edible mushrooms are usually characterized by a pleasant flavor and odor; non-edible varieties have sometimes an unpleasant odor, and produce a biting, burning sensation on the tongue and throat, even in very small quantities, but several of the Amanitas have only a slight odor and taste, and certain species of mushrooms, acrid otherwise, become edible when cooked.
In fact there is no general rule by which the edible species can be distinguished from the unwholesome or poisonous ones. The safest as well as the most sensible plan, therefore, is to apply the same rule as that which we adopt in the case of the esculents among the flowering plants, viz., to learn to know the characteristics of each individual species so as to distinguish it from all others.
With regard to the mushrooms which have been designated as poisonous, it should be remembered that the term "poisonous" is used relatively. While some are only slightly poisonous, producing severe gastric irritation and nervous derangement, but without fatal results, others, if eaten in even very small quantity, may cause death. Happily, however, the most dangerous species are not numerous as compared with the number that are edible, and with careful attention on the part of the collector they may be avoided.
Since the Amanita group is made responsible by competent authority for most of the recorded cases of fatal poisoning, we would recommend the amateur mycophagist to give special study to this group in order to learn to separate the species authentically recorded as edible from the poisonous ones.
Some writers, as a measure of precaution, counsel the rejection of all species of Amanita. But this is, of course, a matter for individual preference. There would seem to be no good reason why the observant student should not learn to discriminate between the edible and the poisonous species of the Amanita as of any other group, and they should not be eaten until this discriminating knowledge is acquired.
Saccardo describes fifteen edible species of this group of mushrooms. We have tested three of this number, which, on account of their abundance in our locality and their good flavor, we would be loth to discard, viz., A. rubescens, A. Cæsarea, and A. strobiliformis.
A type of the Amanita group, which is named first in the genera of the order Agaricini, is shown in Fig. 1, [Plate B].
By reference to this figure some of the special characteristics of the group can be observed. There are mushrooms in other genera which show a volva or sheath at the base of the stem, and which contain edible species, but in these the stem is ringless. The Volvariæ, for instance, show a conspicuous volva, a stem that is ringless, and pinkish spores. The Amanitopsis vaginata carries a volva, but no ring. The spores are white, as in the Amanita.
In gathering mushrooms either for the table or for the herbarium, care should be taken not to leave any portion of the plant in the ground, so that no feature shall be lost that will aid in characterizing the species. In the careless pulling up of the plant the volva in the volvate species is often left behind.