This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Campanula rapunculoides, L
Introduced. Perennial. Propagates by seeds and by rootstocks.
Time of bloom: July to August.
Seed-time: August to September.
Range: New Brunswick to Ontario, southward to Pennsylvania and Ohio. Habitat: Fields and roadsides.
An escape from gardens. The plant does all its "creeping" underground by means of slender, horizontal rootstocks. Above ground it sends up numerous stems one to three feet tall, rather stout, smooth or sometimes finely hairy, simple or with one or two branches near the top. Leaves alternate, long-pointed ovate, heart-shaped at base, irregularly toothed, the lower ones with petioles, the upper ones sessile, diminishing in size as they ascend the stalk. Flowers in a slender, one-sided, bracted raceme, each corolla a large, five-pointed, nodding, purple bell, an inch or more long, the "clapper" being its long, white style with three-cleft, curving stigma; stamens five, alternate with the corolla lobes. The flowers unfold from the base upward, leaving behind a string of globular, three-celled smooth capsules, opening by three valves at the base. Seeds small and very numerous. (Fig. 286.)
The plant forms spreading patches, which, if not too large, may be grubbed out, care being taken to get every shred of the root-stocks; or the latter may be starved by close and repeated cuttings throughout the growing season, salt being used on the shorn surfaces in order to check new growth.
Fig. 286. - Creeping Bellflower (Campanula rapunculoides). X 1/4.