This section is from the book "Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc.", by George Francis Atkinson. Also available from Amazon: Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc..
In the collection of the higher fungi it is of the utmost importance that certain precautions be employed in obtaining all parts of the plant, and furthermore that care be exercised in handling, in order not to remove or efface delicate characters. Not only is it important for the beginner, but in many instances an "expert " may not be able to determine a specimen which may have lost what undoubtedly seem, to some, trivial marks. The suggestions given here should enable one to collect specimens in such a way as to protect these characters while fresh, to make notes of the important evanescent characters and to dry and preserve them properly for future study. For collecting a number of specimens under a variety of conditions the following list of "apparatus" is recommended :
One or two oblong or rectangular hand baskets, capacity from 8-12 quarts.
Or a rectangular zinc case with a closely fitting top (not the ordinary botanical collecting case).
Half a dozen or so tall pasteboard boxes, or tins, 3 x 3, or 4 x4, x 5 inches deep, to hold certain species in an upright position.
A quantity of tissue paper cut 8 x 10 or 6 x 8 inches.
Smaller quantity of waxed tissue paper for wrapping viscid or sticky plants.
Trowel; a stout knife; memorandum pad and pencil.
During the proper season, and when rains are abundant, the mushrooms are to be found in open fields, waste places, groves and woods. They are usually more abundant in the forests. Especially in dry weather are specimens more numerous in rather damp woods, along ravines or streams. In collecting specimens which grow on the ground the trowel should be used to dig up the plant carefully, to be sure that no important part of the plant is left in the ground. After one has become familiar with the habit of the different kinds the trowel will not be necessary in all cases. For example, most species of Russula, Lactarius, Tricholoma, Boletus, etc., are not deeply seated in the soil, and careful hand-picking will in most cases secure specimens properly, especially if one does not object to digging in the soil with the fingers. But in the case of most species of Amanita, certain species of Lepiota, Collybia, etc., a trowel is necessary to get up the base of the plant in such a way as to preserve essential characters. Even then it is possible, if the ground is not too hard, to dig them out with the fingers, or with a stout knife, but I have often found specimens which could only be taken up with a trowel or spade.
Species growing on sticks or leaves are easily collected by taking a portion of the substratum on which they grow. Specimens on the larger limbs or trunks or stumps can sometimes be "picked," but until one is accustomed to certain individualities of the plant it is well to employ the knife and to cut off a portion of the wood if necessary, to avoid cutting off the base of the stem.
It is necessary also to handle the specimens with the greatest care to avoid leaving finger marks where the surface of the stem or cap is covered with a soft and delicate outer coat, especially if one wishes to photograph the plant, since rubbed or marked places spoil the plant for this purpose. Also a little careless handling will remove such important characters as a frail annulus or volva, which often are absolutely necessary to recognize the species.
Having collected the specimens, they should be properly placed in the basket or collecting case. Those which are quite firm, and not long and slender, can be wrapped with tissue paper (waxed tissue paper if they are viscid or sticky), and placed directly in the basket, with some note or number to indicate habitat or other peculiarity which it is desirable to make at the time of collection. The smaller, more slender and fragile, specimens can be wrapped in tissue paper (a cluster of several individuals can be frequently rolled up together) made in the form of a narrow funnel and the ends then twisted. The shape of the paper enables one to wrap them in such a way as to protect certain delicate characters on the stem or cap. These can then be stood upright in the small pasteboard boxes which should occupy a portion of the basket. A number of such wrappers can be placed in a single box, unless the specimens are of considerable size and numerous. In these boxes they are prevented from being crushed by the jostling of the larger specimens in the basket. These boxes have the additional advantage of preserving certain specimens entire and upright if one wishes later to photograph them.