Flora Pittsburghensis

Author: Father Pitt

  • Zigzag Aster (Aster prenanthoides)

    Now Symphyotrichum prenanthoides. This is probably our most common roadside blue aster. The Zigzag Aster is so named from its crooked stem (which also gives it the name “Crooked-Stemmed Aster”).This plat was growing along a trail in Bethel Park, where it was blooming in early October.

    Asters laugh at the notion of “species,” as Gray notes in his description of the genus, so it’s always best to regard any identification, even a fairly sure one like this, as tentative.

    Flowers. Heads about an inch and a quarter wide, in irregular corymbs; disk flowers yellow, fading to red-brown; rays pale blue or violet, sometimes white, linear, numerous.

    Leaves. Variable: alternate; lanceolate or ovate-lanceolate, with sharp and narrow points; strong central rib; rough, outward-facing hairs noticeable when rubbed toward stem; lower leaves on petioles with broad wings clasping the stem; upper sessile and clasping. On some plants the leaves are jaggedly toothed; on others the teeth are less prominent, with the upper leaves almost entire.

    Stem. Tough, wiry; with purplish vertical lines; arching, about 1 or 2 feet high; characteristically zigzag from leaf to leaf, as in the picture at right.

    Gray describes the genus Aster and the species:

    ÁSTER [Tourn.] L. STARWORT. FROST-FLOWER. ASTER. Heads many-flowered, radiate; the ray-flowers in a single series, fertile. Bracts of the involucre mure or less imbricated, usually with herbaceous or leaflike tips. Receptacle flat, alveolate. Achenes more or less flattened; pappus simple, of capillary bristles (double in §§ 4 and 5). — Perennial herbs (annual only in §§ 7 and 8), with corymbed, panicled, or racemose heads, flowering chiefly in autumn. Rays white, purple, blue, or pink; the disk yellow, often changing to purple. Species often without sharply defined limits, freely hybridizing. (Name aster, a star, from the radiate heads of flowers. )

    A. prenanthoìdes Muhl. Stem 1 m. or less high, corymbose-panicled, hairy above in lines; leaves rough above, smooth underneath, ovate to lanceolate, sharply cut-toothed in the middle, conspicuously taper-pointed, and rathrr abruptly narrowed to a long contracted entire portion, which is abruptly dilated into a conspicuously auricled base; heads on short divergent peduncles; involucre 5-8 mm. high; bracts narrowly linear, tips recurved-spreading; rays violet. — Borders of streams and rich woods, w. N. E. to Va. and Ky., w. to Minn, and la. Aug.-Oct.

  • Boneset (Eupatorium perfoliatum)

    A thoroughwort worthy of the name: the stems go right through the paired leaves. The name “Boneset” refers to its supposed assistance in setting broken bones.According to the ancient Doctrine of Signatures, the all-wise Creator has embedded a secret sign in each useful herb to show us what it can be used for: in this case, the joined leaves are supposed to show us that the herb can join what has been broken. Modern scientists have concluded that the all-wise Creator wasn’t as dumb as all that and must have given us a surer way to find useful medicines, which is why we have the scientific method.

    Boneset likes a wet location; this plant was growing in a roadside ditch near Cranberry, where it was blooming in late August.

    Gray describes the genus and the species:

    EUPATÒRIUM [Tourn.] L. THOROUGHWORT. Heads discoid, 3-many-flowered; flowers perfect. Involucre cylindrical or bell-shaped, of more than 4 bracts. Receptacle flat or conical, naked. Corolla 6-toothed. Achenes 6-angled ; pappus a single row of slender capillary barely roughish bristles. — Erect perennial herbs, often sprinkled with hitter resinous dots, with generally corymbose heads of white, bluish, or purple blossoms, appearing near the close of summer. (Dedicated to Eupator Mithridates, who is said to have used a species of the genus in medicine.)

    1. EUPATORIUM proper. Receptacle flat.

    Heads 8-20-flowered; involucre of 8-15 more or less imbricated and unequal bracts, the outer ones shorter; flowers white or nearly so.

    Leaves sessile or nearly so, with a broad base, opposite or in threes; heads pubescent.

    Leaves opposite, clasping or united at the base, long, widely spreading; heads 10-40-flowered; corymbs very compound and large.

    E. perfoliàtum L. (THOROUGHWORT, BONESET.) Stem stout, 0.5-1.6 m. high, hairy; leaves lanceolate, united at the base around the stem (connateperfoliate), tapering to a slender point, serrate, very veiny, wrinkled, downy beneath, 1-2 dm. long; bracts of the involucre linear-lanceolate. — Low grounds; common and well known.

  • White Snakeroot (Eupatorium rugosum)

    Now classified as Ageratina altissima by most botanists, the genus Eupatorium having been broken up into a number of smaller concerns by the FTC.

    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. These plants grew at the edge of the woods in Mount Lebanon, where they were blooming in the middle of September.

    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.

    Gray lists this plant as Eupatorium urticaefolium:

    EUPATÒRIUM [Tourn.] L. THOROUGHWORT. Heads discoid, 3-many-flowered; flowers perfect. Involucre cylindrical or bell-shaped, of more than 4 bracts. Receptacle flat or conical, naked. Corolla 6-toothed. Achenes 6-angled ; pappus a single row of slender capillary barely roughish bristles. — Erect perennial herbs, often sprinkled with hitter resinous dots, with generally corymbose heads of white, bluish, or purple blossoms, appearing near the close of summer. (Dedicated to Eupator Mithridates, who is said to have used a species of the genus in medicine.)

    1. EUPATORIÜM proper. Receptacle flat.

    Heads 5-30-flowered; involucral brada nearly equal, in one row or but a very few of the outermost shorter; leaves opposite, ovate, petioled, triple-nerved, not resinous-dotted.

    Leaves broadly ovate; flowers pure white.

    E. urticaefòlium Reichard. (WHITE SNAKEROOT.) Smooth, branching, 0.5-1 m high; leaves broadly ovate, pointed, coarsely and sharply toothed, long-petioled, thin, 7-12 cm. long; corymbs compound. (E. ageratoides L. f.) — Rich woods, not rare. Var. villicaúle Fernald. Stems and petioles viscidvillous. — Pa. (Heller) to Va. (Curtías).

  • Giant Knotweed (Fallopia sachalinensis)

    Also known as Sachalin. The lesser-known of two beautiful but pernicious Japanese invaders, Giant Knotweed closely resembles its cousin the Japanese Knotweed (F. japonica), but can be distinguished by the leaves, which are longer and pointier and have a heart-shaped base rather than the rounded base of F. japonica. Like the Japanese Knotweed, Giant Knotweed can form large colonies that completely exclude other species of vegetation. These plants grew in an old German cemetery in Beechview, where they were blooming in the middle of September.

    Because this imported weed was not so weedy in Gray’s time, we turn to the on-line Flora of North America at efloras.org:

    Fallopia Adanson, Fam. Pl. 2: 277, 557. 1763.
    [name conserved]

    False-buckwheat [for Gabriello Fallopio, 1532-1562, Italian anatomist] Craig C. Freeman, Harold R. Hinds. Bilderdykia Dumortier.

    Vines or herbs, annual or perennial; roots fibrous or woody; sometimes rhizomatous. Stems erect to scandent, rarely procumbent, glabrous or pubescent. Leaves deciduous, cauline, alternate, petiolate; ocrea persistent or deciduous, chartaceous; petiole base articulated, extrafloral nectaries sometimes present; blade broadly ovate to triangular, margins entire or wavy. Inflorescences terminal and spikelike, or terminal and axillary and paniclelike or racemelike, pedunculate or not. Pedicels present. Flowers bisexual, or bisexual and unisexual, some plants with bisexual flowers, other plants with only pistallate flowers 1-5 per ocreate fascicle, base stipelike; perianth usually accrescent in fruit, pale green or white to pink, campanulate, glabrous or, rarely, with blunt, hyaline hairs; tepals 5, connate nearly completely or only basally, petaloid, dimorphic, outer 3 winged or keeled, larger than inner 2; stamens 6-8; filaments distinct, free, glabrous or pubescent proximally; anthers yellow to pink or red, ovate to elliptic; styles 3, spreading, connate basally or nearly completely; stigmas capitate, fimbriate, or peltate. Achenes included or exserted, brown to dark brown or black, not winged, 3-gonous, glabrous. Seeds: embryo straight. x = 10, 11.

    Species ca. 12 (8 in the flora): North America (including Mexico), South America, Europe, Asia, Africa.

    Herbs, perennial, rhizomatous, 2-4(-5) m. Stems usually clustered, erect, sparingly branched, herbaceous, stiff, glabrous, glaucous. Leaves: ocrea persistent or deciduous, brownish, cylindric, 6-12 mm, margins oblique, face without reflexed and slender bristles at base, otherwise glabrous or puberulent; petiole 1-4 cm, glabrous; blade ovate-oblong, 15-30(-40) × 7-25 cm, base cordate, margins entire, glabrous or scabrous to ciliate, apex obtuse to acute, abaxial face minutely dotted, glaucous, with hairs along veins distinctly multicellular, 0.2-0.6 mm, tips acute to acuminate, adaxial face glabrous. Inflorescences axillary, mostly distal, erect or spreading, paniclelike, 3-8 cm, axes puberulent to pubescent; peduncle 0.1-4 cm or absent, puberulent to reddish-pubescent. Pedicels ascending or spreading, articulated proximal to middle, 2-4 mm, glabrous. Flowers bisexual or pistillate, 4-7 per ocreate fascicle; perianth accrescent in fruit, greenish, 4.5-6.5 mm including stipelike base, glabrous; tepals obovate to elliptic, apex obtuse to acute, outer 3 winged; stamens 6-8; filaments flattened proximally, glabrous; styles connate basally; stigmas fimbriate. Achenes included, brown, 2.8-4.5 × 1.1-1.8 mm, shiny, smooth; fruiting perianth glabrous, wings flat to undulate, 1.8-2.2 mm wide at maturity, decurrent on stipelike base to articulation, margins entire. 2n = 44, 66, 102, 132 (Japan, Korea).

    Flowering Jul-Oct. Disturbed places; 0-500 m; introduced; B.C., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que.; Calif., Conn., Del., Idaho, Ill., Ky., La., Maine, Md., Mass., Mich., Mont., N.J., N.Y., N.C., Ohio, Oreg., Pa., R.I., Tenn., Vt., Va., Wash., W.Va., Wis.; Asia (Japan); introduced in Europe.

    Fallopia sachalinensis was introduced as a soil binder and garden ornamental. Like F. japonica, it spreads aggressively and has been declared noxious in California, Oregon, and Washington. It hybridizes with F. japonica, yielding F. ×bohemica. The mid-stem inflorescences of F. sachalinensis usually are shorter than the subtending leaves.

  • Climbing False Buckwheat (Fallopia scandens)

    This ubiquitous vine looks a bit like a bindweed until it starts to bloom; then the characteristic clusters of tiny flowers of the knotweed clan reveal themselves. Like bindweeds, it likes to clamber over a fence or an arbor, or—as it did here—over the weeds and shrubbery at the edge of the woods. These vines were growing at the edge of an old cemetery in Beechview, where they were blooming in the middle of September.

    Older botanists placed this genus in the large and polymorphous genus Polygonum. Gray describes that genus, the section Tinaria in which he places this species, and the species itself:

    POLÝGONUM [Tourn ] L. KNOTWEED. Calyx 4-6(mostly 5)-parted; the divisions often petal-like, all erect in fruit, withering or persistent. Stamens 3-9. Styles or stigmas 2 or 3; achene accordingly lenticular or 3-angular. Embryo placed in a groove on the outside of the albumen and curved halfway around it; the radicle and usually the cotyledons slender. Pedicels jointed. — Ours all herbaceous, with fibrous roots (except in P. viviparum), flowering through late summer and early autumn. (Name composed of poly-, many, and gonu, knee, from the numerous joints.)

    § 6. TINIÀRIA Meisn. Twining (except dwarf var. of no. 29), unarmed; leaves ovate-heart-shaped; flowers in panicled racemes; outer calyx-lobes keeled or winged.

    P. scándens L. (CLIMBING FALSE BUCKWHEAT.) Perennial, smooth; sheaths naked; leaves heart-shaped or slightly halberd-shaped, pointed; racemes interrupted, leafy; the 3 outer calyx-lobes strongly keeled and in fruit broadly winged, 10-15 mm. long; the wings often crisped, subentire; achene smooth and shining, 4 mm. long. (P. dumetorum, var. Gray.) — Moist thickets, common except on our northern borders. —Twining 2-4 m. over bushes. (Japan.)