The basidia are formed on the end of threadlike branched bodies which grow at the apex, and are called hyphæ. On top of the basidia are minute stalk-like branches, called sterigmata (singular sterigma), and each branch carries a naked spore. They are usually four in number. This group of Basidiomycetes is divided into (1) Stomach fungi (Gasteromycetes),
(2) Spore sac fungi (Ascomycetes), and (3) Membrane fungi (Hymenomycetes).
[MYCELIUM.]
The Mycelium is commonly called the spawn of mushrooms.
It is the vegetative part of the fungus, and is composed of minute, cylindrical, thread-like branching bodies called hyphæ. When we wish to cultivate mushrooms we plant the spawn not the spores. The thread-like branches permeate the earth or whatever the mushroom grows upon. The color of the mycelium is generally white, but it may also be yellow or red. Its structural details are only visible through a microscope.
Every fungus does not bear the spores exposed upon the cap nor underneath it. The first group of Gasteromycetes, or “Stomach fungi,” as Professor Peck has called them in his work on “Mushrooms and Their Uses,” have the spore-bearing surface enclosed in a sac-like envelope in the interior of the plant. The genus Lycoperdon belongs to this group, and it contains the puff-balls so common in this country.
In the second group, Ascomycetes, or “Spore sac fungi,” the spores are produced in delicate sacs called asci. The fruit-bearing part is often cup-shaped, disc-like, or club-shaped, thicker at the top or covered with irregular swellings and depressions like the human brain.
The Morels and Helvellas belong to this group. One often meets with mushrooms of the former genus in the spring, and they are striking and interesting looking fungi. There are many of both genera that are edible. They will be described in detail later.
Botanists have classified Agarics by means of the color of the spores, and it is the only sure way of determining to what class they belong. We propose in this work also to enumerate the mushrooms according to the color of the pileus or cap, and give a list, with a description of each, after this arrangement. This, of course, is merely superficial, but may interest and attract a beginner in the study of fungi. This list will be placed at the end of the book.
The descriptions will be preceded by a classification according to color of spores, some hints to students, and aids to learning which have been found useful to others.