Brook Saxifrage (Saxifraga rivularis) lives in wet places alongside brooks and in moist meadows. It has light green stems with distinctive shiny green leaves with scalloped edges. Each stem bears one to five small white flowers with petals twice the length of sepals.
Saxifrage means "rock breaker" and may derive from the plants living in rocky areas. This stand of saxifrage was on the top of a moist tundra hummock.
Comment: Hummocks are humps of ground which are elevated above the base soil of the tundra. In a well developed hummock area the hummocks are roughly the same size with matching vegetation (one kind of plant on the hummock top and another kind in the crevices between them). One theory of hummock formation indicates that winter freezing forms polygonal cracks in the soil and summer meltwater flows into these cracks enlarging them and rounding the polygons into hummocks with troughs between them.
Anyone walking on the tundra has had the quandry of whether to stay on the tops of the hummocks or to try to walk in the troughs between them. My short legs demand that I dance on the top of the hummocks.