Morchella populiphila is a species of morel fungus (family Morchellaceae) native to northwestern North America. Described as new to science in 2012, its specific epithet refers to its association with black cottonwood (Populus trichocarpa). The morel used to be referred to as Morchella semilibera in western North American field guides until molecular analysis established that to be a strictly European species. M. populiphila occurs in California, Nevada and Oregon. Its fruit bodies grow up to 15 cm (6 in) tall with a ridged and pitted conical cap that attaches about halfway down the stipe. The cap ridges are dark brown to black in maturity, while the pits are yellowish to brownish. The fungus is edible, although not as highly valued as other morels. Morchella populiphila is one of three species of fungi commonly referred to as "half-free" morels, the others being Morchella punctipes in eastern North America and Morchella semilibera in Europe.