Comments: Dry or mesic prairies, glades, rich or rocky woods, in mountains and piedmont, along bluff escarpments and thickets, calcareous river flats or rocky summit communities, near or on the banks of watercourses, in open or thin canopy which can be due to nature or un-natural disturbance (e.g., powerline right-of-ways, along railroad tracks, roadsides). It may have soil preferences (Lindsey, 1990). The western var. occidentalis more closely restricted to moist habitats than the typical eastern var. aptera.
In Connecticut, it is found on the edge of second growth woods and on low bluffs along rivers (Murray 1989).
In Illinois, it is found in wet prairies in the north, and in limestone glades in the south (Karnes 1989).
In Indiana, all of the known populations occur on dry, thinly forested limestone slopes and glades (Homoya 1990).
In Iowa, it occurs especially in dry to mesic prairies with a circumneutral soil (Leoschke 1990).
In Michigan, it occurs on hillside prairies (steep and gravelly) in the southwestern Lower Peninsula, with Bessya bullii, Bouteloua curtipendula, Quercus prinus, Heuchera sp., Andropogon sp. and other prairie species (Penskar 1989). The northern, Mackinac County Population covers several acres of man-made mesic clearings on calcareous glacial till (Penskar 1989). Other species there include Achillea millefolium, Carex crawei, C. capillaris, C. castanea, Campanula rotundifolia, Castilleja coccinea, Chrysanthemum leucanthemum, Cypripedium calceolus, Juncus balticus, Lilium philadelphicum, Potentilla fruticosa, Prunella vulgaris, and Rudbeckia hirta (Penskar 1989).
In Minnesota, it is most common in "wet mesic to mesic prairie but also in dry mesic and dry prairies and dry woods (but not on sand prairies). It occurs in oak and pine woods..." (Sather 1989).
In Missouri, it is "most often at the edge of carbonate glades and throughout open woodlands bordering the glades" (Nigh 1989).
In Montana, it is "relatively widespread in moist habitats...in moist, brushy thickets, very near or on the banks of watercourses" (Shelly 1989).
In New Jersey, it occurs in the northern Ridge and Valley, Highlands, and Piedmont areas, and infrequently on the Inner Coastal Plain. Snyder has seen it "most abundant in dampish soil or seepage areas on trap rock or database (sic) and in similar conditions within our limestone region" (1989).
In Ohio, the typical habitat is "grassy or barren opening over thin, calcareous soil. Typical associates include: Andropogon gerardii, A. scoparious, Bouteloua curtipendula, Silphium terebinthianaceum and Solidago rigida. In Belmont County in eastern Ohio it grows on talus below an exposure of low-grade limestone. The Franklin County sire is on glacial till exposed on an eroded bluff above a stream" (Cusick 1990).
In Pennsylvania, one site on a limestone bluff is a calcareous rocky summit community containing two rare species, Chrysogonum virginianum and Dodecatheon meadia (Edinger 1989). Other species include Quercus alba, Q. rubra, Q. velutina, Carya laciniosa, Juniperus virginiana, Ostrya virginiana, Staphylea trifolia, Saxafraga virginiensis, Hypoxis hirsuta, Potentilla simplex, and Lonicera japonica (Rhoads and Mellon 1984).
In South Carolina, it is most often found in the mountains and piedmont, or bluffs on the coastal plain. In wet piedmont sites dominated by soils of the Iredell series, it can be found with Zizia aurea, Thalictrum revolutum, Camassia scilloides, Geranium maculatum, Podophyllum peltatum, and Saxifraga virginiensis (Nelson 1989).
In South Dakota, it has been found in habitats characterized by Pinus ponderosa or Populus tremuloides/Corylus cornuta (Hoffman and Alexander 1987). A study of soils in Deuel County found Z. aptera in poorly drained Flom soil (Hubbard et al. 1987).
In Virginia, it is most often found where the soils are circumneutral to basic, with associates Polygala senega, and Scutellaria leonardii (Ludwig 1989).