Half Free Morel (Morchella Semilibera)
Morchella semilibera, commonly called the half-free morel, is an edible species of fungus in the family Morchellaceae native to Europe and Asia. DNA analysis has shown that the half-free morels, which appear nearly identical on a macroscopic scale, are a cryptic species complex, consisting of at least three geographically isolated species. The half-free morels, Morchella punctipes and Morchella populiphila, have caps that are attached about halfway down the stem, creating a substantial overhang where the margin of the cap hangs around the stem. Though the two species cannot be separated on the basis of their physical features, they are separated by geography; Morchella punctipes appears in hardwood forests from the Great Plains eastward, while Morchella populiphila appears under black cottonwoods in northwestern North America.
Both species used to be called “Morchella semilibera”–before a recent DNA study (O’Donnell and collaborators, 2011) found support for the idea that Morchella semilibera is a strictly European species, and that our North American species are genetically distinct. Many of my morel-hunting comrades in the Midwest, God love ’em, call the half-free morels “peckerheads.”
The name “punctipes” was applied by a North American mycologist, Charles Peck (1903) to a Michigan half-free morel that was sent to him (he was based in New York state) and which featured what he called a “squamulose stem,” for which “[t]he adornment . . . consists of small conical points which are sometimes darker colored than the stem and are then more conspicuous.” Thus, Peck coined the epithet punct – ipes (spotted – stem) and named a new species because, in his estimation, the usual half-free morel (Morchella semilibera) had a smooth stem. Peck’s ideas are supported by the Friesian description of Morchella semilibera (1822), which says: “stipite laevi” (stem smooth).
I have not collected the European Morchella semilibera, so I am not speaking from personal experience . . . but O’Donnell and collaborators (2011) found support for only one half-free morel in Europe, and photos of what must therefore be this mushroom on the Internet and in European field guides easily demonstrate that the stem of the European half-free morel, like the stems of its North American counterparts, is often adorned with the “small conical points” mentioned by Peck, but is sometimes more smooth and is occasionally nearly bald. In other words, the presence or absence of the spots on the stem appears to be a highly variable character, and Peck’s idea is not supported.
However, Peck named a morel and, regardless of whether his concept held water his name still applies according to the rules of taxonomy. Thus Kuo and collaborators (2012) applied Peck’s epithet to the eastern North American half-free morel rather than name a new species (we were also able to validate a better known Peck morel species, Morchella angusticeps).
Ecology: Possibly saprobic and mycorrhizal at different points in its life cycle; growing alone, scattered, or gregariously under hardwoods in various forest types; common in some years and rare or absent in others; March to May; widely distributed east of the Rocky Mountains.
Cap: 2-4.5 cm tall and 2-4.5 cm wide; conical or broadly conical (rarely nearly convex); pitted and ridged, with the pits primarily arranged vertically; when young with bald, flattened, yellowish brown to pale brownish ridges, and whitish to pale yellowish pits; when mature developing flattened to sharpened, dark brown to black ridges and yellowish brown to brownish pits; attached in a skirt-like manner to the stem, about halfway from the top; hollow.
Stem: 1.5-15 cm high and 1-4.5 cm wide; often hidden under the cap when young, but lengthening dramatically with maturity; fragile; in warm, wet conditions becoming inflated, especially toward the base; sometimes developing longitudinal furrows; white to watery brownish; usually mealy with whitish granules that sometimes darken to brown, but sometimes nearly bald; hollow.
Spore Print: Yellowish orange to whitish.