Cypripedium candidum Willd.
Common Name: WHITE LADY-SLIPPER
Coefficient of Conservatism: 10
Coefficient of Wetness: -5
Wetness Index: OBL
Physiognomy: Nt P-Forb
Status: T

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 C. 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. Occasional hybrids with C. parviflorum (C. ×andrewsii Fuller) are striking, typically with pale yellow to ivory lips and relatively dark sepals and petals.

Locations

Berrien County
Calhoun County
Cass County
Hillsdale County
Huron County
Ionia County
Jackson County
Kalamazoo County
Kent County
Lapeer County
Lenawee County
Livingston County
Macomb County
Oakland County
St. Clair County
Tuscola County
Van Buren County
Washtenaw County
Wayne County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 11, 2017. http://www.michiganflora.net/species.aspx?id=1805.