Campanulastrum americana ID

Photos below are Campanulastrum americana / Tall Bellflower, a Carolinian native listed as “common” in Hamilton (Ontario) area in Michael Oldham’s ‘List of the Vascular Plants of Ontario’s Carolinian Zone (Ecoregion 7E)’ (link opens in new tab) . Formerly known as Campanula americana and recently assigned its own genus Campanulastrum, this is an unusual bellflower, growing to 6′ tall (5′ in my garden) and preferring shade.

It’s a biennial that forms a rosette in the first season and then sends up a tall flowering stem the next summer. If you collect seeds and plant seedlings two years in a row (and also allow plants to re-seed) you’ll have these beauties every year. Take photos and make notes on the location so you don’t weed out your bellflower seedlings in the spring.

Campanulastrum americana / Tall Bellflower

In my garden (Hamilton Ontario, ecodistrict 7E-3) Campanulastrum americana blooms in mid-July. I allow plants to re-seed next to a south-facing wooden fence shaded by asters, goldenrod, and a Chionanthus virginicus / White Fringetree. I expect the blooms to become darker blue as the Fringetree matures and the area becomes more shaded.

Comparing my photos to those on the excellent plant database at Texas A&M’s Lady Bird Johnson Wildflower Centre, (opens in new tab) I’m confident that this is our beautiful native Tall Bellflower. Last year some bellflowers came up in another part of my garden, in an area that’s I’d grown this one in the past. These turned out to be the dreaded C. rapunculoides. The young plants, thankfully, were easy to remove.

If you’re confronting this invasive, I feel your pain. But it IS possible to remove an infestation if you recognize your target and act quickly. Be sure to look for the “parsnip” taproot, which grows from the rhizomatous root system starting anywhere from 4 to 12″ underground, depending on the soil texture and moisture availablilty.

This graphic shows the telltale “parsnip” taproot of Campanula rapunculoides.

Be sure to remove every trace of rhizome as well as the taproot. This plant will regrow from pieces left behind.

Discard–do not compost.

The following photos will serve as a reminder to me to NOT ASSUME anything– and to keep better records. The original seed for these came from J.L. Hudson in California, more than a decade ago. I’m very glad to still have these beauties, despite last year’s shocking (terrifying?) experience.

I will definitely save seeds from these plants, but anyone who is given seeds is reminded of the responsibility to trust your source and your ID, especially when a gorgeous native plant may resemble an invasive thug.

Leave a Reply