Morels are some of the most sought-after wild mushrooms. They grow in many parts of the United States, and are considered delicious by mushroom lovers. Morels are the reproductive structures of fungi in the genus Morchella. Although the mushrooms are the most visible part, the majority of the fungus remains hidden, with its filamentous cells (called hyphae) forming a network under the ground .
Morels fruit in most parts of the United States under trees in deciduous, coniferous or mixed forests, and occasionally in fields, yards or on disturbed ground. In Texas, they appear on limestone-based soil among junipers. In most parts of the country, they appear for a few weeks in the spring after rains, but in Southern states they are known to come up in the fall as well. In California, they pop up just about any time.
Most mushrooms rot or shrivel up after a few days but morels tend to be more persistent, sometimes lasting for weeks after making their initial appearance. There are four kinds of true morels--yellow, black, white and half-free.
Yellow morels (Morchella esculenta), as the common name suggests, can be yellow, golden, tan or brown. These mushrooms have a spongy-looking cap, hence another common name for the morel--sponge mushroom. The caps of all morels are sinuous and almost brain-like in appearance.
Yellow morels can appear just about anywhere if the conditions are right, but are most common under hardwood trees as the weather warms up after a cold winter. This morel species is found from late winter to early summer and is more common in the Eastern and Midwestern parts of America, less so in the West.
The black morel (Morchella elata) has a darker cap than either the yellow or white morel, especially in age. Cap color ranges from yellowish-brown to dusky black. Black morels are common in the Northern and Western parts of the United States in spring or early summer. This morel species is especially known for its appearance on burned ground during the years following forest fires. As is true of all morels, the stems of black morels are hollow.
The white morel (Morchella deliciosa) is a small- to medium-sized morel with pale, light-colored ridges on the cap. The pits (the open regions between the cap ridges) tend to be large and widely spaced compared to other morels. This species is found all over, although it is usually limited to later in the spring in the eastern United States. Morels are fickle and sometimes appear widely scattered or sometimes all in a bunch at unexpected times in unexpected places.
Half-free morels (Morchella semilibera) look a little different than the other three kinds of morels. If a half-free morel is cut lengthwise through its stem, the bottom part of the cap is seen to be unattached to the stem. Yellow, black, and white morels have caps that are fully inter-grown with and attached to the stem. Even though the cap is brain-like, it tends to be more conical and have a shape reminiscent of a typical mushroom cap as found on most other kinds of familiar mushrooms. This species is more brittle and the least delicious of the four kinds of morels.