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 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 species is usually quite stout, though it varies to some extent in some of the different species, in proportion to the thickness of the cap. The stem is marked in some of the species by large wrinkles or folds extending irregularly but with considerable uniformity over the surface. The surface is further minutely roughened by whitish or grayish elevations, giving it a granular appearance. Sometimes these granules are quite evenly distributed over the surface, and in some species they are more or less separated into small areas by narrow lines.
The morels appear early in the season, during May and June. They grow usually in damp situations, and are more abundant during rainy weather. Three species are illustrated here.
Morchella esculcnta Pers. Edible. - The name of this species, the esculent morel, indicates that it has been long known as an edible plant, especially since the man who named it lived a century ago. The plant is from 5-15 cm. high, the stem is 1-3 cm. in thickness, and the cap is broader than the stem. The cap is somewhat longer than broad, and is more or less oval or rounded in outline. The arrangement of the pits on the surface of the cap is regarded by some as being characteristic of certain species. In this species the pits are irregularly arranged, so that they do not form rows, and so that the ridges separating them do not run longitudinally from the base toward the apex of the cap, but run quite irregularly. This arrangement can be seen in Fig. 216, which is from a photograph of this species. The stem is hollow.
Morchella conica Pers. Edible. - This species is very closely related to the preceding one, and is considered by some to be only a form of the Morchella esculenta. The size is about the same, the only difference being in the somewhat longer cap and especially in the arrangemerit of the pits. These are arranged more or less in distinct rows, so that the ridges separating them run longitudinally and parallel from the base of the cap to the apex, with connecting ridges extending across between the pits. The cap is also more or less conic, but not necessarily so. Figure 217 illustrates this species. The plant shown here is branched, and this should not be taken to be a character of the species, for it is not, this form being rather rare.
Morchella conica (natural size). Copyright.
Plate 86, Figure 218
Morchella crassipes (natural size). Copyright.
Morchella crassipes (Vent.) Pers. Edible. - This species differs from the two preceding in the fact that the stem is nearly equal in width with the cap. Figure 218 illustrates a handsome specimen which was 17 cm. high. The granular surface and the folds of the stem show very distinctly and beautifully. Collected at Ithaca.
Morchella deliciosa Fr. Edible, has the cap cylindrical or nearly so. It is longer than the stem, and is usually two or three times as long as it is broad. The plant is smaller than the preceding, though large ones may equal in size small ones of those two. The plant is from 4-8 cm. high.
Morchella semilibera DC, and M. bispora Sor., [Verpa bohemica (Kromb.) Schroet.] occur in this country, and are interesting from the fact that the cap is bell-shaped, the lower margin being free from the stem. In the latter species there are only two spores in an ascus.