UNGI, HELVELLAS, ETC.: DISCOMYCETES.

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
desirable to accomplish it in such a work as the present. Certain of the
species will then be described and illustrated.

[Illustration: PLATE 85, FIGURE 216.--Morchella esculenta (natural
size). Copyright.]

MORCHELLA Dill.

The morels are all edible and they are usually easy to recognize. The
plant consists of two distinct, prominent parts, the cap and the stem.
The cap varies in form from rounded, ovate, conic or cylindrical, or
bell-shaped, but it is always marked by rather broad pits, covering the
entire outer surface, which are separated from each other by ridges
forming a network. The color of the plants does not differ to any
perceptible extent in our species. The cap is usually buff or light
ochre yellow, becoming darker with age and in drying.

The stem in all our spec