Campanula glomerata ‘Superba’
Clustered Bellflower. A vigorous, variable, rhizomatous, clump-forming perennial which has ovate to lance-shaped, round-toothed, dark green leaves. From June to August, dense, terminal racemes of purple-violet, bell-shaped flowers are borne.
Grow in moist but well-drained, fertile, neutral to alkaline soil in sun or partial shade. It will reach a height of 60cm and an indefinite spread.