Tree species associated with "Morchella" vary greatly depending on the individual species, continent, or region. Trees commonly associated with morels in Europe and across the Mediterranean include "Abies" (fir), "Pinus" (pine), "Populus" (poplar), "Ulmus" (elm), "Quercus" (oak), "Arbutus" (strawberry trees), "Castanea" (chestnut), "Alnus" (alder), "Olea" (olive trees), "Malus" (apple trees) and "Fraxinus" (ash). In western North America morels are often found in coniferous forests, including species of "Pinus" (pine), "Abies" (fir), "Larix" (larch), and "Pseudotsuga" (Douglas-fir), as well as in "Populus" (cottonwood) riparian forests. Deciduous trees commonly associated with morels in the northern hemisphere include "Fraxinus" (ash), "Platanus" (sycamore), "Liriodendron" (tulip tree), dead and dying elms, cottonwoods and old apple trees (remnants of orchards). Due to their springtime phenology (March–May), morels are hardly ever found in the vicinity of common poisonous mushrooms such as the death cap ("Amanita phalloides"), the sulphur tuft ("Hypholoma fasciculare"), or the fly agaric ("Amanita muscaria"). They can, however, occur alongside false morels ("Gyromitra" and "Verpa" species) and elfin saddles ("Helvella" species), which also appear in spring.