Andromeda polifolia is a small shrub in the heath family (Ericaceae), found in black spruce muskeg, bogs and wet sedge meadows (and also rarely in alpine tundra on limestone). It is the only member of its genus occurring in Denali, and easily recognizable by the rosemary-like linear leaves and the urn-shaped bright pink flowers. Plants grow 10-50 cm tall. The leaves are thick-leathery, linear and with a rolled margin, 12-25 mm long. They are dark green above and bright white below, both surfaces hairless. Leaves are alternately arranged, encircling the red-brown stems. There are 1-4 perfect flowers at the end of a twig, nodding at the end of thick pink pedicels. The pink fused petals are squat-globose to round, constricted at the tip with a few small lobes. Fruits are an inedible fleshy pink capsule, containing 1-44 seeds. Although called 'bog rosemary' A. polifolia should definitely not be consumed, because it contains a neurotoxin.
The leaves of bog rosemary are evergreen. The species flowers in early to mid-summer.
Andromeda flowers are pollinated by insects, primarily bees and flies (Taylor 2007). A. polifolia is also self-compatible, but self-fertilization reduces seed set (Fröborg 1996). Seeds do not require cold stratification in order to germinate (Jacquemart 1998). Fruits are a fleshy pink capsule, bitter in flavor, containing 1-44 seeds (Jacquemart 1998). Seeds are potentially dispersed by bird consumption, by wind after the decay of the fruit, and by water (Taylor 2007). Plants can also vegetatively reproduce from rhizomes.
The plant is mildly toxic, and the fruits are bitter. The species is grown as an ornamental shrub, and some cultivars have been developed.
Andromeda polifolia is a widespread circumpolar species, in North America reaching through all the provinces of Canada south to New England and the Great Lakes states, on the west coast to Washington and Idaho. It is widespread in Alaska, absent only from the western Aleutian Islands. Bog rosemary is common and occurs throughout the boreal lowlands of Denali.
This species is most common below 300 meters (reaching 0.8% cover)and is most frequent in Denali on slopes of less than 4 degrees (sites had an average incline of 2.91 degrees). Sites on inclines, however, are disproportionately likely to be north-facing.