Campanula pilosa syn. Adenophora tricuspidata

Hairy Bellflower from Japan, north to Siberia, and into NW Alaska. Spread by stolons, to form a mat. Glossy bright green. The relatively large, solitary flowers are held atop 5-10 cm stems in summer. Runs about in a joyful way. 

Alpsdake, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons