Flora Pittsburghensis

Category: Compositae

  • 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.

  • Hollow Joe-Pye-Weed (Eutrochium fistulosum)

    Eutrochium fistulosum
    Photographed August 1 with a Konica Minolta DiMAGE Z6.

    Formerly Eupatorium fistulosum, but the genus Eupatorium has been split into several genera. This beautiful and elegantly constructed plant, also known as Trumpetweed, bears domes of dusty mauve flower heads on towers of whorled leaves, usually five to seven in a whorl. The plants can easily grow to seven feet or more. They prefer a damp environment, and are often seen in the soggier parts of roadsides and fields.

    Close-up of the flower heads

    These plants were growing in the native-plant field in Robin Hill Park, Moon Township.

    Hollow Joe-Pye-Weed
    Trumpetweed

    For a description of the species, see the Eutrochium fistulosum reference page.

  • Orange Hawkweed (Hieracium aurantiacum)

    Our only bright orange dandelion-like flower, impossible to confuse with anything else. In many modern classifications this is placed in the genus Pilosella as Pilosella aurantiaca, but the taxonomy is still more confused than old Pa Pitt cares to sort out. It is not a common flower in the city of Pittsburgh, but a little bit to the north it becomes ubiquitous. St. Peter’s Cemetery in Arlington is one of the places in Pittsburgh where Orange Hawkweed does grow, and that is where these plants were photographed.

    Photographed June 24 with a Konica Minolta DiMAGE Z6.