Category: Asteraceae

  • Dandelion (Taraxacum officinale)

    Taraxacum officinale

    It’s the middle of April, and cheery yellow dandelions are everywhere. We always have room for more pictures of them.

    Dandelion
    Three heads
    Dandelions
  • Coltsfoot (Tussilago farfara)

    Tussilago farfara
    Photographed April 8.

    Coltsfoot is one of our earlier spring flowers. It likes the edge of the woods, but it can sprout almost anywhere; these plants were growing at the edge of a parking lot in Banksville. The blooming stalks come straight out of the ground before any leaves appear.

    Coltsfoot

    Coltsfoot is a European import, but around here it is not invasive enough to be a pest.

    For a fuller description, see the Tussilago farfara reference page.

    Nodding heads
  • Purple-Stemmed Aster (Symphyotrichum puniceum)

    Symphyotrichum puniceum
    Photographed October 11.

    Formerly Aster puniceus. These common blue asters like slopes above streams and squishy wet ground. These grew on the bank of a brook near Wexford. They are quite variable: Britton & Brown say that “races differ in pubescence, leaf-form, and leaf-serration,” meaning that anything you say about the shape of the leaves or how rough or hairy they are has to be followed by the words “or not.” The leaves of these plants were rough and sandpapery, and the stem quite hairy. The name puniceum, or Punic (“having to do with Phoenicia”), was doubtless suggested by the deep Tyrian-purple color of the stems.

    Purple-stemmed aster
    Aster puniceus

  • White Snakeroot (Ageratina altissima)

    Photographed September 20.

    In older references this plant is Eupatorium rugosum, but the genus Eupatorium has been divided into several more manageable genera. These plants were growing at the edge of St. Michael’s Cemetery on the South Side Slopes; White Snakeroot often forms dense stands right at the border between field and forest.

    It makes bees happy.

    Here is what we wrote about White Snakeroot twelve years ago:

    One of our most decorative late-summer and autumn flowers, White Snakeroot lights up the edge of the woods and can form a perfect ornamental border around a field. Its beauty comes at a price: it’s poisonous to cattle, and the poison can be transmitted through their milk. “Milk sickness” killed Abraham Lincoln’s mother. But if you don’t have cattle, there’s no reason not to enjoy this beautiful wild native.

    As a member of the Composite family, this species is especially interesting for the way the individual little five-parted flowers are easily distinguishable in the heads. It’s a good plant for demonstrating the construction of a Composite flower to children.

    Flowers: Heads discoid (that is, with no ray flowers), in irregular flattish corymbs; flowers pure white, with protruding stamens, also white.

    Leaves. Opposite; oval, pointed, toothed, finely rough; underside with many prominent ribs; lower leaves flattish at base or almost cordate; on petioles about 1/3 the length of the leaves.

    Stem: Smooth, flexible; much branched from leaf axils; averaging about 4 feet, but quite variable and can be much taller.

  • Sneezeweed (Helenium autumnale)

    Helenium autumnale
    Photographed August 26.

    We last looked at Helenium autumnale in 2015. Since then it has become very well established in that meadow in Schenley Park. We repeat the text of the earlier article:

    Sneezeweed is an attractive composite flower with distinctively notched rays that make it easy to identify. (A similar species, Purple-Headed Sneezeweed, Helenium flexuosum, has been introduced in a few locations; it is easy to distinguish by the dark brownish button in the center.) The plant likes damp areas; this one was growing in Schenley Park, in a section of former lawn that is being allowed to grow into a meadow for better water retention. It was blooming in the middle of September.

    Habit of the plant

    Gray describes the genus and the species:

    HELÈNIUM L. SNEEZEWEED. Heads many-flowered, radiate; rays several, wedge-shaped, 3-6-cleft, fertile, rarely sterile. Involucre small, reflexed; the bracts linear or awl-shaped. Receptacle globose or ellipsoid. Achenes top-shaped, ribbed; pappus of 6-8 thin 1-nerved chaffy scales, the nerve usually extended into a bristle or point. — Erect branching herbs with alternate leaves, often sprinkled with bitter aromatic resinous globules; heads yellow, rarely purple, terminal, single or corymbed. (The Greek name of some plant, said to be named after Helenus, son of Priam.)

    Leaves broad, decurrent on the angled stem.

    H. autumnàle L. Perennial, nearly smooth, 0.2-2 m. high; leaves mostly toothed, lanceolate to ovate-oblong; heads larger (2-4 cm. broad); disk yellow; rays fertile, yellow. — Alluvial river-banks and wet ground, w. Que. and w. Mass. to Man., southw. and westw. Aug.-Oct.

    Sneezeweed
    Helenium autumnale