Fens, wet, calcareous meadows, usually with tamarack and shrubby cinquefoil, wet prairies (at least formerly); very local. An old (July 1884) Farwell collection purported to be from Keweenaw County is surely a label error and is not mapped.

Herbarium specimens for which the collector failed to note flower color on the label sometimes resemble dry material of small-flowered plants of Cypripedium parviflorum. The 3–4 leaves of C. candidum are crowded toward the middle of the stem, their bases overlapping and concealing the internodes; in C. parviflorum, the leaves tend to be less crowded, with the internodes visible. The lip of dry C. candidum specimens ranges from 1.6 to 2.5 cm long; the dorsal sepal, from 20 to 30 (–33) mm long; and the lateral petals are less than 37 (–40) mm long. In C. parviflorum, the lip is often over 2.5 cm long, the dorsal sepal often over 30 mm long, and the lateral petals almost always over 37 mm long, but smaller flowers are found. There is a clear tendency for the orifice of the lip to be more acute at the front than in C. parviflorum, but this can be hard to judge in a pressed herbarium specimen. Fruiting collections are not reliably identifiable. 

Occasional hybrids with C. parviflorum (C. × andrewsii Fuller) are striking, typically with pale yellow to ivory lips and relatively dark sepals and petals. Hybrids are scarce in fens and sedge meadows, with collections known from Berrien, Huron, Jackson, Kalamazoo, Lenawee, Oakland, and Washtenaw Cos. These are almost all crosses with C. parviflorum var. makasin, the hybrid with the var. pubescens is very rare. The Berrien Co. occurrence may represent this variant. 

The lip typically has purple dotting on the inside, near the orifice, and purpe lines. Pure white forms lacking this color occur occasionally.