This is the very edible and very delectable morel mushroom (Morchella sp., Morchellaceae). Every spring many mushroom hunters scour temperate wooded areas in search of these culinary prizes. When sliced and sauteed in butter, the meaty, succulent flavor is distinct and arguably unrivaled among edible mushrooms.
In the eastern US, morels are often found near a variety of hardwood trees including elm, tulip tree, cottonwood, sycamore, ash, cherry, and apple. They seem especially prominent in forests affected by fire, though the reason isn’t well known.
These mushrooms are found exclusively in the spring. The peak season is anywhere from early April to late May here in southern Michigan, but this varies by latitude. It’s a bit earlier to the south, and a bit later to the north. The season also depends on the weather. Morels need moist ground and low temperatures consistently in the 40s F or above.
Part of what makes them so valued is that efforts at commercial production have met limited success. There seems to be some key combination of growing conditions that are necessary but are largely unknown and unreproducible in cultivation. Because of this, wild mushrooms remain the only real source. They can be hard to find, but it can be worth a few leisurely hours (if you’re lucky) to enjoy their flavor.
As with any mushroom, it’s extremely important to be completely certain of the identification before consumption. Some toxic mushrooms superficially resemble morels, and it’s best to assume a mushroom is poisonous unless you know otherwise. Morels themselves are mildly toxic when raw, and should always be cooked before being consumed. This paper provides some more insight on morel identification, biology, and taxonomy.