Potentilla arenosa subsp. arenosa
Petioles with both long verrucose hairs and a lower layer of common to abundant short and/or stiff crisped hairs. 2n = 28; 42, 49, 56, 70 (Asia).
Phenology: Flowering spring–summer.
Habitat: Well-drained gravel, ridge tops, cliffs, dry soil banks, dry tundra
Elevation: 0–1400 m
Greenland, Alta., B.C., Man., N.W.T., Nunavut, Sask., Yukon, Alaska, Asia (Siberia)
Plants of subsp. arenosa from Alaska and Yukon tend to be larger, with more open inflorescences and more distinctly petiolulate central leaflets, than plants in north-central Canada. Some collections from the range of Potentilla furcata (sect. Rubricaules) have red glands in the inflorescence, suggesting introgression between P. arenosa and P. furcata. Reported occurrences in Alberta and Saskatchewan (and the upper altitudinal limit given here) might actually be P. hookeriana as now circumscribed.
"dm" is not declared as a valid unit of measurement for this property.