Salix arctophila Cockerell ex Heller
Habitat: Barrens, meadows and alpine regions. [Alpine or subalpine (non-forested, upland)]
Range: Greenland and eastern Arctic regions, south to alpine barrens of southern Canada and Mt. Katahdin.
Aids to Identification: Willows are recognized by their winter buds and flowers: their buds are covered by a single, cap-like scale, and their willow flowers are very small and are borne in catkins. Identification of willows is complicated by the fact that these plants are dioecious - the staminate and carpellate flowers are borne on separate plants. Maine has 5 species that occur above tree-line. Salix arctophila is recognized by the following combination of characteristics: low, mat forming shrub rarely taller that 30 cm high; entire leaves (or nearly so) with a thin bloom on the underside; large (up to 6 mm long), purple buds.
Ecological characteristics: The only occurence of this species in Maine was documented from above treeline on Mount Katahdin on a remote granite slab. It occurs as a single staminate plant.
Phenology: Flowers mid-June - July.
Synonyms: Salix arctica Liebm.; Salix arctophila Cockerell ex Heller var. lejocarpa Anderss.) Schneid.; Salix groenlandica Lundstr.; Salix groenlandica Lundstr. var lejocarpa (Anderss.) Lange.
Known Distribution in Maine: This rare plant has been documented from a total of 1 town(s) in the following county(ies): Piscataquis.
Reason(s) for rarity: Disjunct from principal range.
Conservation considerations: Known population is small and subject to the vagaries of small populations like random fluctuations or localized disturbance events.