Morchella esculenta, (commonly known as common morel, morel, yellow morel, true morel, morel mushroom, and sponge morel) is a species of fungus in the family Morchellaceae of the Ascomycota. It is one of the most readily recognized of all the edible mushrooms and highly sought after. Each fruit body begins as a tightly compressed, grayish sponge with lighter ridges, and expands to form a large yellowish sponge with large pits and ridges raised on a large white stem. The pitted yellow-brown caps measure broad by tall, and are fused to the stem at its lower margin, forming a continuous hollow. The pits are rounded and irregularly arranged. The hollow stem is typically long by thick, and white to yellow. The fungus fruits under hardwoods and conifers during a short period in the spring, depending on the weather, and is also associated with old orchards, woods and disturbed grounds. Taxonomy and naming The fungus was originally named Phallus esculentus by Carl Linnaeus in his Species Plantarum (1753), and given its current name by Swedish mycologist Elias Magnus Fries in 1801. Morchella esculenta is commonly known by various names: morel, common morel, true morel, morel mushroom, yellow morel, sponge morel, Molly Moocher, haystack, and dryland fish. In Nepal it is known as Guchi chyau. The specific epithet is derived from the Latin esculenta, meaning "edible". The scientific name Morchella esculenta has been applied to many similar yellow morels throughout the world. In 2014 Richard et al. used DNA analysis to restrict the M. esculenta name to a single species of yellow morel commonly found in Europe and also reported from China. Other species of yellow morel, including those in North America, have received new scientific names. Description The cap is pale brownish cream, yellow to tan or pale brown to grayish brown. The edges of the ridges are usually lighter than the pits, and somewhat oval in outline, sometimes bluntly cone-shaped with a rounded top or more elongate. Caps are hollow, attached to the stem at the lower edge, and typically about broad by tall. The flesh is brittle. The stem is white to pallid or pale yellow, hollow, and straight or with a club-shaped or bulbous base. It is finely granular overall, somewhat ridged, generally about long by thick. In age it may have brownish stains near the base. It has a passing resemblance to the common stinkhorn (Phallus impudicus), for