Studies of American Fungi. Mushrooms, Edible, Poisonous, etc.

by George Francis Atkinson

Smaller quantity of waxed tissue paper for wrapping viscid or sticky plants.

Trowel; a stout knife; memorandum pad and pencil.

Collecting.—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.

Field Notes.—The field notes which may be taken upon the collection will depend on circumstances. If one goes to the sorting room soon after the collection is made, so that notes can be made there before the more delicate specimens dry, few notes will answer in the field, and usually one is so busy collecting or hunting for specimens there is not much inclination to make extended notes in the field. But it is quite important to note the habitat and environment, i. e., the place where they grow, the kind and character of the soil, in open field, roadside, grove, woods, on ground, leaves, sticks, stumps, trunks, rotting wood, or on living tree, etc. It is very important also that different kinds be kept separate. The student will recognize the importance of this and other suggestions much more than the new "fungus hunter."

Sorting Room.—When one returns from a collecting trip it is best to take the plants as soon as possible to a room where they can be assorted. An hour or so delay usually does not matter, but the sooner they are attended to the better. Sometimes when they are carefully placed in the basket, as described above, they may be kept over night without injury, but this will depend on the kinds in the collection. Coprini are apt to deliquesce, certain other specimens, especially in warm weather, are apt to be so infested with larvæ that they will be ruined by morning, when immediate drying might save them. Other thin and delicate ones, especially in dry weather, will dry out so completely that one loses the opportunity of taking notes on the fresh specimen. Specimens to be photographed should be attended to at once, unless it is too late in the day, when they should be set aside in an upright position, and if necessary under a bell-jar, until the following day. As far as possible good specimens should be selected for the photograph, representing different stages of development, and one to show the fruiting surface. Sometimes it will be necessary to make more than one photograph to obtain all the stages. Also on different days one is apt to obtain a specimen representing an important stage in development not represented before. The plants should be arranged close together to economize space, but not usually touching nor too crowded. They should be placed in their natural position as far as possible, and means for support, if used, should be hidden behind the plant. They should be so arranged as to show individual as well as specific character and should be photographed if possible natural size, or at least not on a plate smaller than 5 × 7 inches unless the plants are small; while larger ones are better on 6 × 8 or larger. Some very small ones it may be necessary to enlarge in order to show the character of the fruiting surface, and even large specimens can sometimes have a portion of the hymenium enlarged to good advantage if it is desirable to show the characters clearly. The background should be selected to bring out the characters strongly, and in the exposure and developing it is often necessary to disregard the effect of the background in order to bring out the detail of texture on the plant itself. The background should be renewed as often as necessary to have it uniform and neat. There is much more that might be said under this head, but there is not space here.

To Obtain Spore Prints.—In many cases it is desirable to obtain spores in a mass on paper in order to know the exact tint of color produced by the species. Often the color of the spores can be satisfactorily determined by an examination of them under the microscope. One cannot always depend on the color of the lamellæ since a number of the species possess colored cystidia or spines in the hymenium which disguise the color of the spores. The best way to determine the color of the spores in mass is to catch them as they fall from the fruiting surface on paper. For the ordinary purpose of study and reference in the herbarium the spores caught on unprepared paper, which later may be placed in the packet with the specimen, will answer. This method has the advantage of saving time, and also the danger of injury to the spores from some of the fixatives on prepared paper is avoided. If for purposes of illustration one wishes pretty spore prints, perfect caps must be cut from the stem and placed fruiting surface downward on paper prepared with some gum arable or similar preparation spread over it, while the paper is still moist with the fixative, and then the specimen must be covered with a bell-jar or other receiver to prevent even the slightest draft of air, otherwise the spores will float around more or less. The spores may be caught on a thin, absorbent paper, and the paper then be floated on the fixative in a shallow vessel until it soaks through and comes in contact with the spores. I have sometimes used white of egg as a fixative. These pieces of paper can then be cut out and either glued to card-boards, or onto the herbarium sheet.

Sorting the Plants.—This should be done as soon as possible after collection. A large table in the sorting room is convenient, upon which the specimens may be spread, or grouped rather, by species, the individuals of a species together, on sheets of paper. Surplus dirt, or wood, leaves, etc., can be removed. A few of the specimens can be turned so that spores can be caught on the papers. If only one or a few specimens of a given species have been found, and it is desirable not to cut off the cap from the stem, the plant can be supported in an upright position, a small piece of paper slit at one side can be slipped around the stem underneath the cap, on which the spores will fall. Sometimes it will be necessary to cover the plant with a bell-jar in order to prevent it from drying before the spores are shed. Experience with different species will suggest the treatment necessary.