Flora Pittsburghensis

Category: Compositae

  • 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.

  • Tall Thoroughwort (Eupatorium altissimum)

    Eupatorium altissimum

    These dusty white thoroughworts are a Midwestern species that began to invade our area in the middle 1900s. They are now ubiquitous, but mostly along the railroads and highways by which they invaded.

    Tall Thoroughwort

    For a description of the species, see the Eupatorium altissimum reference page.

    Eupatorium altissimum
    Tall Thoroughwort
    Photographed September 24 with a Canon PowerShot SX150 IS.

  • Lance-Leaved Goldenrod (Euthamia graminifolia)

    Euthamia graminifolia
    Photographed September 19 with a Konica Minolta DiMAGE Z6.

    The only flat-topped goldenrod in the Pittsburgh area, so it is easy to identify. This plant was making bees happy next to a bridge over Montour Run in Moon Township.

    For a thorough description, see the Euthamia graminifolia reference page.