Comments: Juglans cineara typically grows in rich mesophytic forests, lower slopes, ravines, and various types of bottomland, including banks and terraces of creeks and streams, and floodplain forests (Fernald 1950, Gleason and Cronquist 1991). This species achieves its best growth in well-drained bottomland and floodplain soils.
The following provides additional information on the specific habitats of J. cinerea in several states from different parts of the species' range:
The habitat in Ohio is mesic river terraces and ravines (Cusick 1992).
Michigan habitat includes streambanks, swamp forests, and upland beech-sugar maple, oak-hickory, and mixed hardwood stands (Voss 1985). In southern Michigan sites, associates may include such species as Ulmus americana (American elm), Acer saccharinum (silver maple), Fraxinus quadrangulata (blue ash), Betula alleghaniensis (yellow birch), Tilia americana (basswood), and many woodland and swamp herbs. In some areas, butternut occurs occasionally as a roadside tree.
The habitat in Illinois and Wisconsin is mesic and riparian hardwood forests, where associates of the overstory include Acer saccharum (sugar maple), Carpinus caroliniana (blue beech), Celtis occidentalis (hackberry), Fagus grandifolia (American beech), Prunus serotina (black cherry), Quercus alba (white oak), Quercus macrocarpa (bur oak), Quercus rubra (red oak), Tilia americana (basswood), and Ulmus americana (American elm). The herbaceous associates of this habitat include Claytonia virginiana (spring beauty), Dicentra cucullaria (squirrel corn), Hydrophyllum appendiculatum (appendaged waterleaf), Isopyrum biternatum (false meadow-rue), and Solidago caesia (woodland goldenrod). In wooded floodplain habitats, associate plant species include Celtis occidentalis, Cryptotaenia canadensis (honewort), Elymus virginicus (Virginia rye grass), Fraxinus pennsylvanica (red ash), Galium aparine (cleavers), Geum canadense (geum), Hydrophyllum virginianum (Virginia waterleaf), Laportea canadensis (wood nettle), Ranunculus septentrionalis (swamp buttercup), Toxicodendron radicans (poison ivy), Rudbeckia laciniata (cutleaf coneflower), Ulmus americana, and Viola sororia (woolly blue violet). A characteristic habitat in the Chicago region is springy, wooded, calcareous slopes, where limey water percolates through gravelly soils. Associate plant species in this habitat may include Angelica atropurpurea (angelica), Caltha palustris (marsh marigold), Cardamine bulbosa (spring cress), Fraxinus nigra (black ash), Lilium michiganense (Michigan lily), Mitella diphylla (bishop's cap), Ribes americanum (swamp gooseberry), Smilacina stellata (starry false solomon's seal), Solidago patula (swamp goldenrod), and Symplocarpus foetidus (skunk cabbage) (Swink and Wilhelm 1979).
The habitat in Indiana is mesic forests (Homoya 1992).
The typical habitat in Kentucky is mesic wooded ravines along streams, mesic limestone gorges, mesic deciduous forest, second growth in mixed hemlock forest, and upland mesic woods, occurring with Fraxinus americana (white ash), and several other species (KY HP 1992).
In Tennessee, Juglans cinerea occurs along creek bottoms in mesic forests and on lower slopes (TN ESD 1992).
In Mississippi, this species occurs on calcareous bluffs, along river and stream drainages, in mesophytic forests, and calcareous ravines. Populations are often found on north-facing slopes. Associate plant species include Acer spp. (maple), Carya spp. (hickory), Juglans nigra (black walnut), Liriodendron tulipifera (tuliptree), and Quercus macrocarpa (bur oak) (MS NHP 1992).
Habitat in Delaware consists of northwest-facing slopes of pastures, banks of streams running through meadows, and floodplain woods with partial shade (DE NHP 1992).
In Massachusettes this species a generalist in terms of soil moisture (it's found along a continuum from river bottomlands to mesic forests to talus and dry balds) but it does not seem to be a generalist in terms of bedrock substrate-in MA it avoids acid, nutrient poor substrates and appears to be restricted to areas underlain by basalt, marble, or dolomite (M. Dow Cullina, pers. comm., 2006).