Rivals Canada Goldenrod for sheer yellow spectacle, but comes out in October and into November, after the Canada Goldenrods have mostly gone to seed. Note the long rays on the individual heads, giving the whole tuft of yellow a distinctive shaggy look. These plants were blooming in mid-October under a streetcar overpass in Beechview. Gray lists this as Solidago serotina var. gigantea.

From Gray’s Manual: S. serotina Ait. Stem stout, 0.6-2.5 m. high, smooth, often glaucous; leaves quite smooth both sides, lanceolate to oblanceolate, taper-pointed, very sharply serrate, except the narrowed base, rough-ciliate; the middle ones 7-16 cm. long, 1-3 cm. wide; the ample panicle pubescent; involucre 3.5-5 mm. long, its bracts linear, subherbaceous; rays 7-14, rather long. Thickets, in rich soil, N. B. to B. C., and southw. July-Sept.

Var. gigantea (Ait.) Gray. Leaves glabrous above, slightly pubescent beneath, especially on the nerves; involucre 3.2-4 mm. long. Low ground, e. Que. to Ill., and southw.

Also called Milfoil, “thousand-leaf,” from the finely divided leaves. A European import that has become a common wildflower all over the East. Still a popular garden flower; in recent years many colors have been bred, but the wild ones are almost always either white or pink. This plant, blooming in mid-October, grew by the side of a country road a little west of Houston, Pennsylvania.

Gray describes the genus and the species:

ACHILLEA [Vaill.] L. YARROW
Heads many-flowered, radiate; the rays few, fertile. Involucral bracts imbricated, with scarious margins. Receptacle chaffy, flattish. Achenes oblong, flattened, margined; pappus none. Perennial herbs, with small corymbose heads. (So named because its virtues are said to have been discovered by Achilles.)

A. millefolium L. (COMMON Y., MILFOIL.) Stem simple or sometimes forked above, 3-10 dm. high, arachnoid or nearly smooth; stem-leaves numerous (8-15), smooth or loosely pubescent; corymbs very compound, 6-20 cm. broad, flat-topped, the branches stiff; involucre 3-5 mm. long, its bracts all pale, or in exposed situations the uppermost becoming dark-margined; rays 5-10, white to crimson, short-oblong, 1.5-2.5 mm. long. Fields and river-banks, common. (Eurasia.)

These tall, sunny-yellow flowers often grow at the edge of the woods. They are also called “Yellow Ironweed”; although they are not closely related to the true ironweeds (Vernonia altissima and Vernonia noveboracensis, for example), the plants look very similar without the flowers, and the stems are similarly strong. The flowers are distinctive: the rays are presented in a slovenly sort of way, with some flowers never growing more than two of them. The flowers with more rays often look like a sloppy drawing of a daisy, with rays of different sizes and shapes arranged asymmetrically.  The disks are spiny-looking, with large florets arranged pincushion-fashion.

From Gray’s Manual:

ACTINOMERIS Nutt.
Heads many-flowered; rays neutral, few or none. Involucral bracts few, herbaceous, nearly equal, soon deflexed beneath the globular disk. Receptacle small, chaffy. Achenes flat, obovate, winged or wingless, at maturity spreading in all directions; pappus of 2-3 smooth persistent awns. Tall branching perennials, with serrate feather-veined leaves tapering to the base and mostly decurrent on the stem. Heads corymbed; flowers chiefly yellow. (Name from aktis, a ray, and meris, a part;  alluding to the irregularity of the rays.)

1. A. alternifolia (L.) DC. Stem somewhat hairy, usually winged above, 1-2 m. high; leaves alternate or the lower opposite, oblong or ovate-lanceolate, pointed at both ends; rays 2-8, irregular. (A. squarrosa Nutt.; Verbbesina alternifolia Britton.) Rich soil, N. J. to Ont., Ia., Kan., and southw. Aug.-Sept.

The common Sunflower is often seen along the Pennsylvania Turnpike, but also in urban lots. Originally a native of the Midwest, it springs up happily enough in Pittsburgh wherever anyone has been feeding sunflower seeds to the birds. If it grows tall enough, late in the season it produces many smaller flowers in the leaf axils, as here. This plant was blooming in early October on a hillside by one of Beechview’s many public stairways.

From Gray’s Manual: H. annuus L. (COMMON SUNFLOWER.) Tall, rough; leaves triple-ribbed ovate or the lower cordate, serrate; involucral bracts broadly ovate to oblong, long-pointed, ciliate; disk usually 2.5 cm. broad or more. Rich soil, Minn, to Tex., and westw.; long cultivated, and occasionally found in waste grounds eastw.

Hard to distinguish from Tall Ironweed, with which it apparently hybridizes. The height is a clue, but conditions can make Tall Ironweed as short as New York Ironweed. This specimen was found in an old cemetery in Beechview. Gray puts Pittsburgh out of the range of New York Ironweed, but most other authorities agree in placing it here. The distinction between Vernonia altissima and Vernonia noveboracensis is sketchy enough, however, that all our ironweeds may be races of the same species. In any event, the Tall Ironweed seems to be our most common.

The vivid purple of the ironweeds makes them one of our most spectacular native flowers, and enlightened gardeners are beginning to adopt them as ornamentals.

Gray describes the genus and the species:

VERNONIA Schreb. IRONWEED
Heads discoid, 16-many-flowered, in corymbose cymes; flowers perfect; involucre shorter than the flowers, of much imbricated bracts. Achenes cylindrical, ribbed; pappus double, the outer of minute scale-like bristles, the inner of copious capillary bristles. Perennial herbs, with leafy steins, alternate acuminate or very acute serrate leaves and mostly purple (rarely white) flowers. (Named for William Vernon, an early English botanist, who traveled in North America. )

V. noveboracensis Willd. Rather tall (1-2 m.); leaves long-lanceolate to lance-oblong, more or less pubescent beneath, gradually narrowed but not at all acuminate toward the base; cyme open; heads mostly 30-40-flowered; involucre purplish (or in white-flowered individuals green), campanulate; the bracts ovate or lance-ovate, with loosely ascending or recurved-spreading filiform tips; pappus purple or purplish. Low ground near the coast, Mass, to Va. and Miss.; reported from Pelee I., L. Erie (Macoun).