Flora Pittsburghensis

Category: Compositae

  • Philadelphia Fleabane (Erigeron philadelphicus)

    Erigeron philadelphicus
    Photographed May 17.

    Philadelphia Fleabane is found in many of the same places as Common or Daisy Fleabane (Erigeron annuus), and the two can be hard to tell apart at first glance. Philadelphia Fleabane has even more rays—usually more than a hundred per flower head—giving the heads a shaggy appearance. As we see above, Philadelphia Fleabane is also more likely to show a pink tinge or occasionally a strong pink color, but that is not a reliable indicator, since many Philadelphia Fleabanes are pure white. These plants were growing in a large patch along a street in Beechview.

    Philadelphia Fleabane close up

    This common weed can tolerate some shade, so we often see large patches of it in lightly shaded overgrown areas near parking lots or roads.

    Philadelphia Fleabane

    For a description of the species, see the Erigeron philadelphicus reference page

    Erigeron philadelphicus, habitus

    In the picture above, note how the heads in bud are nodding—hanging down—before they open.

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  • Spanish Needles (Bidens bipinnata)

    Bidens bipinnata flower head

    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.

    Seeds of Bidens bipinnata
    Photographed September 28 with a Konica Minolta DiMAGE Z6.

    For a description of the species, see the Bidens bipinnata reference page.

  • Blue Wood Aster (Symphyotrichum cordifolium)

    Symphyotrichum cordifolium
    Photographed September 26.

    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.

    Blue Wood Aster
    Heartleaf Aster
    Photographed September 25.
    Aster cordifolius
    Symphyotrichum cordifolium
    Blue Wood Aster
    Aster cordifolius

  • Chicory (Cichorium intybus)

    Cichorium intybus

    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.

    Chicory
    Photographed September 24 with a Canon PowerShot SX150 IS.

    For a description of the species, see the Cichorium intybus reference page.

  • Mistflower (Conoclinium coelestinum)

    Copnoclinium coelestinum

    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
    Photographed August 9 with a Konica Minolta DiMAGE Z6.

    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.

    Conoclinium coelestinum
    Conoclinium coelestinum
    Photographed September 27 with a Kodak EasyShare Z981.