Flora Pittsburghensis

Author: Father Pitt

  • Spotted Knapweed (Centaurea maculosa)

    These beautiful flowers, close relatives of the garden Bachelor’s Button (Centaurea cyanus), seem to be found almost exclusively along railroads. We have three pictures now of this species, each beside a different railroad; this particular plant was part of a colony growing by the railroad viaduct that separates the South Side Flats from the Slopes, where it was blooming at the end of July. (The other two pictures are here and here.)  The color is variable from purple through white, but this purplish pink is by far the most common color.

    Gray describes the genus and the species:

    CENTAUREA L. STAR THISTLE. Heads many-flowered; flowers all tubular, the marginal often much larger (as it were radiate) and sterile. Receptacle bristly. Involucre ovoid or globose, imbricated; the bracts margined or appendaged. Achenes obovoid or oblong, compressed or 4-angled, attached obliquely at or near the base; pappus setose or partly chaffy, or none. Herbs with alternate leaves; the single heads rarely yellow. (Kentaurie, an ancient Greek plant-name, poetically associated with Chiron, the Centaur, but without wholly satisfactory explanation.)

    C. maculosa Lam. Pubescent or glabrate, with ascending rather wiry branches; involucre ovoid-cainpanulate, in fruit becoming open-campanulate; the outer and middle ovate bracts with rather firm points and with 5-7 pairs of cilia at the dark tip; innermost bracts elongate, entire or lacerate; corollas whitish, rose-pink, or purplish, the marginal falsely radiate. Waste places, roadsides, etc., N. E. to N. J. (Adv. from Eu.)

  • Purple Giant Hyssop (Agastache scrophulariifolia)

    Spelled A. scrophilariaefolia in Gray. Not a terribly common plant around here; this patch was growing in a clearing in Scott, where it was blooming in late August. The flowers are irresistibly attractive to butterflies. The leaves have a noticeable anise scent, not as strong as but very much like the scent of its more commonly cultivated cousin, Anise Hyssop (A. foeniculum). The two species are very similar; the most obvious difference is in the length of the flower spikes, which in A foeniculum are usually not much longer than your thumb, but in this species can easily exceed your longest finger.

    Gray describes the genus and the species:

    AGÁSTACHE Clayt. GIANT HYSSOP. Calyx tubular-bell-shaped, 15-nerved, oblique, 5-toothed, the upper teeth rather longer than the others. Upper lip of corolla nearly erect, 2-lobed, the lower 3-cleft, with the middle lobe crenate. Stamens 4, exserted; the upper pair declined, the lower and shorter pair ascending, so that the pairs cross; anther-cells nearly parallel. —Perennial tall herbs, with petioled serrate leaves, and small flowers crowded in interrupted terminal spikes in summer. (From agan, much, and stachys, an ear of corn, in reference to the numerous spikes.) Lophanthus Benth., in part.

    A. scrophulariaefòlia (Willd.) Ktze. Stem (obtusely 4-angled) and lower surface of the ovate or somewhat heart-shaped acute leaves slightly pubescent: spikes 0.6-5 dm. long; calyx-teeth lanceolate, acute, shorter than the purplish corolla; otherwise like the preceding [A. nepetoides]. (Lophanthus Benth.)—N. H. to Out., Mo., Ky., and Va. Var. Mollis (Fernald) Heller. Stems and lower surfaces of leaves densely villous. — Vt. and Ct. to Ill.

    [Because Gray’s description of this species refers to his description of A. nepetoides, here is that description: 

    A. nepetoides (L.) Ktze. Stem stout, 0.7-1.5 m. high, sharply 4-angled, smooth or nearly so; leaves ovate, somewhat pointed, coarsely crenate-toothed, 6-12 cm. long; spikes 3-12 cm. long, crowded with the ovate pointed bracts; calyx-teeth ovate, rather obtuse, little shorter than the pale greenish-yellow corolla. (Lophanthus Benth.) — Borders of woods, e. Mass., Vt., and w. Que. to Minn., and southw.]

    The famous naturalist William Bartram found this species in New Jersey near Philadelphia, and reported it as Hyssopus scrophularifolius in his Copendium Florae Philadelphicae:

    H. spikes verticillatc, cylindric; styles longer than the corolla; leaves cordate-ovate, acuminate, obtusely dentate.—Wilhl. and Pursh.

    Agastache, Gronovius, Fl. Virg. 88.
    Icon. Herm. parad. t. 106.

    A very rare plant, easily known from the preceding [Agastache nepetoides]. From fourteen inches to two feet high. Flowers purple. On the banks of the Delaware, Jersey side, on the walk from Kaighn’s point to the next ferry below, close to a shady thicket. Perennial. July.

  • Spotted Joe-Pye-Weed (Eupatorium maculatum)

    UPDATE: An earlier version of this article gave the wrong species name in the title.

    Shorter than the more common Hollow Joe-Pye-Weed (E. fistulosum), with flatter cymes, and with leaves commonly in whorls of 4 rather than 6. The two species sometimes grow side by side, as they did here in a damp depression in Schenley Park, where they were both blooming in early August.

    Most botanists today place the Joe-Pye-Weeds in the genus Eutrochium, making this Eutrochium maculatum; we keep the more familiar name for the convenience of Internet searchers.

    Once again, we turn to Alphonso Wood for a description:

    EUPATORIUM.

    Dedicated to Eupator, king of Pontus, who first used the plant m medicine.

    Flowers all tubular; involucre imbricate, oblong; style much exserted, deeply cleft; anthers included; receptacle naked, flat ; pappus simple, scabrous; achenia 5-angled.—Perennial herbs, with opposite or verticillate leaves. Heads corymbose. Flowers of the cyanic series, that is, white, blue, red, &c., never yellow.

    * Leaves verticillate. Flowers purple.

    E. Maculatum. (E. purpureum, ß. Darl.) Spotted Eupatorium.

    Stem solid, striate, hispid or pubescent, greenish and purple, with numeróos glands and purple lines; the glands on the stem and leaves give out an acrid effluvium in flowering-time: leaves. triple-veined, 3-5 in a whorl.—Low grounds, U. S. and Can. Stem 4-6 ft. high. Leaves petiolate, 6-7 in. by 3-4 in., strongly serrate. Flowers purple. July-Sept.

  • Hollow Joe-Pye-Weed (Eupatorium fistulosum)

    Probably the most common species of Joe-Pye-Weed in our area. Most botanists today put Joe-Pye-Weeds in the genus Eutrochium; we keep the name Eupatorium for the convenience of Internet searchers.

    This magnificent plant, with its domes of dusty-rose flowers on towering stems, is common in damp fields and roadsides everywhere; these plants grew in a moist depression in Schenley Park, side by side with their close cousins the Spotted Joe-Pye-Weeds (E. maculatum). Enlightened gardeners who have space for a few eight-foot towers in their perennial beds are beginning to discover and make use of this plant, which can now be seen in some of Pittsburgh’s most tasteful gardens.

    The taxonomy of the Joe-Pye-Weeds seems to be in an awful mess. Alphonso Wood’s Class-Book of Botany seems to be closest to the modern botanists’ classification of this species, so we use Wood’s description here:

    EUPATORIUM.

    Dedicated to Eupator, king of Pontus, who first used the plant m medicine.

    Flowers all tubular; involucre imbricate, oblong; style much exserted, deeply cleft; anthers included; receptacle naked, flat ; pappus simple, scabrous; achenia 5-angled.—Perennial herbs, with opposite or verticillate leaves. Heads corymbose. Flowers of the cyanic series, that is, white, blue, red, &c., never yellow.

    * Leaves verticillate. Flowers purple.

    E. fistulosum Barratt. (E. purpureum Willd. in part. E. incarnatum Linn., in part. E. purpureum, v. angustifolium T. & G.) Trumpet-weed.—Stem fistulous, glabrous, glaucous-purple, striate or fluted; leaves in about 12 whorls of 6s, largest in the middle of the stem, rather finely glandular-serrate; midvein and veinlets livid purple; corymb globose, with whorled peduncles.—Thickets, U. S. and Can., very abundant in the Western States! Height 6-10 ft., hollow its whole length. Leaves, including the 1″ petiole, 8″ by 2″. Corymb often 1 ft. diam. Flowers purple. The glaucous hue and suffused redness of this majestic plant are most conspicuous in flowering-time. It does not appear to possess the acrid properties of E. maculatum. July—Sept.

  • Staghorn Sumac (Rhus typhina)

    An aggressively weedy but beautiful tree; its large leaves have a tropical look, and in the fall they display the most riotously vivid reds and oranges. The little greenish flowers don’t attract much attention, but the beautiful fruit clusters can range from deep mahogany to vivid rose.

    Sumacs belong to the same family that gives us Poison Ivy, but also the tropical cashews and mangoes. For the sake of a mango we can forgive the family anything.

    This tree was growing at the edge of a field in Seven Fields, where it was showing off its staghorns in late July.

    Gray describes the genus and the species, which he places in the Sumac section of the genus Rhus:

    RHÚS L. SUMACH. Calyx small, 5-parted. Petals 5. Stamens 6, inserted under the edge or between the lobes of a flattened disk in the bottom of the calyx. Fruit small and indéhiscent, a sort of dry drupe. — Leaves usually compound. Flowers greenish-white or yellowish. (The old Greek and Latin name.)

    § 1. SUMAC DC. (in part). Flowers polygamous, in a terminal thyreoid panicle; fruit globular, symmetrical, clothed with acid crimson hairs; ttou smooth; leaves odd-pinnate. (Not poisonous.)

    R. typhina L. (STAGHORN S.) Shrub or tree, 1-10 m. high, with orange-colored wood; branches and stalks densely velvety-hairy; leaflets 11-31, pale beneath, oblong-lanceolate, pointed, serrate. (Ii. hirta Sud worth.) — Dry or gravelly soil, e. Que. to Ont., s. to Ga., Ind., and Ia. June, July. — Apparently hybridizes with the next species. Forma Laciniata (Wood) Kehder. Leaflets and bracts more or less deeply and laciniately toothed. — A frequent form, at least in some cases pathological and with inflorescence transformed in part into contorted bracts (the Dalisca hirta of L.). Forma Dissecta Rehder. Leaves bipinnatifld to bipinnate. — An occasional form, now in cultivation.