Campanula lasiocarpa is a tiny perennial alpine forb with outsized solitary violet-blue bell-shaped flowers. Mountain harebell grows in open soil, rocky sites and tundra, rare in the lowlands and very common in well-drained alpine sites. Plants grow 5-10 cm tall, arising from a slender rhizome. Leaves are primarily arranged in a basal rosette 1-3 cm in diameter; blades are elliptic to oblanceolate with coarsely serrate margins on long petioles. Stem leaves are alternate, sessile and reduced. Flowers are usually solitary, perfect, petals fused into with large blue to purple corolla, 1.5-3.5 cm long, having ovate lobes shorter than the tube. The calyx lobes are linear to lanceolate with white hairs with laciniate teeth. Fruits are a many-seeded oblongcapsule opening by pores. The other common species of bellflower in the park, Campanula uniflora lacks dentate leaves and toothedsepals, with the floral tube being much narrower and only slightly longer than the calyx.
Campanula lasiocarpa usually flowers in mid to late summer (July-early August).
Campanula lasiocarpa is monoecious with bisexual flowers. Flowers in the genus Campanula are typically protandrous, the anthers releasing pollen before the stigmas are receptive. Pollen is shed onto the style. If insects visit with pollen from other flowers, cross-fertilization can occur; if not, leftover pollen will self-fertilize the flowers. Flowers are insect pollinated, most likely by bees and wasps. Seeds are wind dispersed.
Campanula lasiocarpa has an amphi-Beringian distribution, occurring in the Russian Far East, China and Japan and then eastward into North America, where this species ranges from Alaska eastward to the Northwest Territories and south to British Columbia, Alberta and Washington state. In Denali, this species is common and widespread in the mountains and hills throughout the Park on both sides of the Alaska Range crest.
Campanula lasiocarpa is an alpine species which is observed from 274 m to 1787 m, with an average plot elevation of 1120 m. Most plants occur at elevations above 1100 m. It is most common on north, northwest, and northeast facing slopes. This taxon prefers steep slopes with an average plot slope of 19 degrees.