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..
The remaining fungi to be considered belong to a very different group of plants than do the mushrooms, puff-balls, etc. Nevertheless, because of the size of several of the species and the fact that several of them are excellent for food, some attention will be given to a few. The entire group is sometimes spoken of as Discomycetes or cup-fungi, because many of the plants belonging here are shaped something like a disk, or like a cup. The principal way in which they differ from the mushrooms, the puff-balls, etc., is found in the manner in which the spores are borne. In the mushrooms, etc., the spores, we recollect, are borne on the end of a club-shaped body, usually four spores on one of these. In this group, however, the spores are borne inside of club-shaped bodies, called sacs or asci (singular, ascus). These sacs, or asci, are grouped together, lying side by side, forming the fruiting surface or hymenium, much as the basidia form the fruiting surface in the mushrooms. In the case of the cup or disk forms, the upper side of the disk, or the upper and inner surface of the cap, is covered with these sacs, standing side by side, so that the free ends of the sacs form the outer surface. In the case of the morel the entire outer surface of the upper portion of the plant, that where there are so many pits, is covered with similar sacs. Since so few of the genera and species of the morels and cup-fungi will be treated of here, I shall not attempt to compare the genera or even to give the characters by which the genera are known. In most cases the illustrations will serve this purpose so far as it is desi-able to accomplish it in such a work as the present. Certain of the species will then be described and illustrated.
Plate 85, Figure 216
Morchella esculenta (natural size). Copyright.