The species name usitatissimum literally means that this is the most commonly used species of flax, and so it is—the source of real linen and flaxseed oil, as well as the source of the purest blue in the cottage garden. It has established itself as an occasional volunteer, especially in areas where it might have been grown commercially at one time: these plants were growing at the edge of a cornfield in Findlay Township.
The flower heads look like tiny marigolds, but the seeds are what you are most likely to notice. They catch in your clothes (or in an animal’s fur, but they almost seem designed for human-made fabrics) and take a ride to some other location that, with any luck, will be hospitable to Bidens bipinnata. These plants were growing against a fence in Beechview.
For a description of the species, see the Bidens bipinnata reference page.
Known as Aster cordifolius in most botanical literature, but the North American Asters have been separated into the genus Symphyotrichum by botanists who enjoy the challenge of a pentasyllabic Greek term. Identifying Asters is hard, because there are many species and they hybridize. This, however, is a very common one. Its generous clusters of small closely spaced blue flower heads decorate our roadsides and brighten woodland trails. The lower leaves are lanceolate with heart-shaped bases, giving the species its name and one of its other common names, “Heartleaf Aster.”
These plants were photographed in Bird Park, Mount Lebanon, and in the Kane Woods Nature Area, Scott Township.
These cheerful sky-blue flowers are everywhere from summer into fall, but they are no less delightful for being common. These were blooming along the Montour Trail in Moon Township.
For a description of the species, see the Cichorium intybus reference page.
Formerly classified in the genus Eupatorium, which was separated into several genera after some genetic research. These dusty blue flowers are distinctive: nothing else quite like them grows around here. They have the tassely flowers of a Joe-Pye-Weed, but the powder-blue color identifies them right away. They resemble a tall version of the garden Ageratum.
Mistflower begins blooming in the middle to late summer, and can still be found blooming into fall. These plants were blooming in Bird Park in Mount Lebanon.
