Diapensia lapponica L.
Habitat: Alpine areas, bare ledges and gravel [Alpine of subalpine (non-forested upland)].
Range: Circumboreal. South to ME, NH, VT, and NY.
Aids to Identification: Diapensia is a tufted alpine sub-shrub with white 5-lobed flowers and opposite leaves. This species grows in very dense "cushions" and mats above treeline. The leaves are small and ovate in shape. Colloquially called a cushion plant.
Ecological characteristics: Found above treeline on Maine's highest mountains. Grows on bare rock and gravel. Maine's populations are Diapensia lapponica var. laponica.
Phenology: Flowering June and July.
Synonyms: None noted
Known Distribution in Maine: This rare plant has been documented from a total of 9 towns in the following counties: Franklin, Oxford, Piscataquis, Somerset.
Dates of documented observations are: 1926 (2), 1947, 1962, 1964, 1965, 1967, 1974, 1981, 1982, 1984 (4), 1996, 1997 (2), 1998, 2000, 2001 (2)
Reason(s) for rarity: Alpine habitat is scarce in Maine, at southern limit of range.
Conservation considerations: Hikers should stay on trail and avoid trampling alpine vegetation.