All known locations of bog adder's-mouth in Minnesota occur in rich conifer swamps dominated by black spruce (Picea mariana) with occasional tamarack (Larix laricina) and balsam fir (Abies balsamea), and rarely northern white cedar (Thuja occidentalis). The orchid grows in semishaded areas, perched on low hummocks of sphagnum and feather mosses, as if not rooted at all. The delicate root system often has only three or four short, threadlike roots that grow no farther down than the surrounding moss.
Flowering begins around mid-July and lasts through August. The plant produces 10 to 29 greenish-yellow flowers with a faint blue-green striped lip. As these tiny flowers (about 5 millimeters long, smaller than a mosquito) mature, the pedicels spirally twist 360 degrees, so that the lip turns upward. (Most orchids twist 180 degrees so that the lip is lowermost in the flower.) The reason for this 360-degree orientation is not known; but perhaps like many orchid adaptations has evolved to attract a specific pollinator.
Stems are typically 5 to 15 centimeters, including the inflorescence. The stems arise from a pseudobulb, which is covered by two to five alternate leaves. Tiny vegetative propagules called foliar embryos sometimes occur on the leaf tips. Once the leaves drop to the ground, these foliar embryos can grow into new adult plants. How often or effective this process is in producing new plants is not known. The only insect observed carrying pollen from this plant has been a species of fungus gnat called Phronia digitata.
Bog adder's-mouth is listed as a state endangered species.
by Erika Rowe