Flora Pittsburghensis

Author: Father Pitt

  • White Avens (Geum canadense)

    This unassuming little member of the rose family likes to grow at the edge of the woods; this plant was growing on a shaded bank in Mount Lebanon, where it was blooming in the middle of June. The white flowers bear more than a passing resemblance to the flowers of blackberries or strawberries.

    Gray describes the genus and the species, which he puts in the Eugeum or Geum-proper division of the genus:

    GEUM L. AVENS

    Calyx bell-shaped or flattish, deeply 5-cleft, usually with 5 small bractlets at the sinuses. Petals 5. Stamens many. Achenes numerous, heaped on a conical or cylindrical dry receptacle, the long persistent styles forming hairy or naked and straight or jointed tails. Seed erect; radicle inferior. Perennial herbs, with pinnate or lyrate leaves. (A plant name used by Pliny.)

    EUGEUM T. & G.  Styles jointed and bent near the middle, the upper part deciduous and mostly hairy, the lower naked and hooked, becoming elongated; head of fruit sessile in the calyx, calyx-lobes reflexed.

    * Petals white or pale greenish-yellow, small, spatulate or oblong; stipules small.

    + Receptacle of the fruit densely hairy.

    G. canadense Jacq. Stem (0.6-1.1 m. high) and petioles sparingly hairy; leaves soft-pubescent beneath or glabrate, the basal of 3-5 leaflets or undivided, those of the stern mostly 3-divided or -lobed, rather sharply toothed; stipules ovate-oblong, 1-1.5 cm. long, subentire; petals white. (G. album J. F. Gmel.) Borders of woods, etc., widely distributed.

  • Poison Hemlock (Conium maculatum)

    This is the plant “by which criminals and philosophers were put to death at Athens,” as Gray observes with  a humor as dry as an herbarium specimen. Most notoriously, the juice killed Socrates. It’s a European import that’s very common in Pittsburgh along roadsides and at the edge of the woods. The plants resemble their relative Queen Anne’s Lace (Daucus carota), but are much taller, with looser umbels borne profusely up and down the strong stems. Often the main stem has a distinctive whitish bloom.

    Needless to say, Poison Hemlock is very poisonous, so mixing it up with edible members of the same family can be a bad mistake. This plant grew on a hillside in Beechview, where it was blooming in the middle of June.

    Gray describes the genus and the species:

    CONIUM L. POISON HEMLOCK
    Fruit somewhat flattened at the sides, glabrous, with prominent wavy ribs; oil-tubes none, but a layer of secreting cells next the seed, the face of which is deeply and narrowly concave. Poisonous biennial, with spotted stems, large decompound leaves with lanceolate pinnatifid leaflets, involucre and involucels of narrow bracts, and white flowers. (Koneion, the Greek name of the Hemlock, by which criminals and philosophers were put to death at Athens.)

    C. maculatum L. A large branching herb, in waste places, Que. to Del., Pa., and westw. (Nat. from Eu.)

    http://florapittsburghensis.com/2009/10/14/queen-annes-lace-daucus-carota/

  • Norway Cinquefoil (Potentilla norvegica)

    Also called Rough Cinquefoil, because it has rough hairs all over. This paradoxical cinquefoil has three leaflets rather than five. It grows in waste places and isn’t too particular about soil; this plant grew in the middle of a gravel driveway near Cranberry, where it was blooming in mid-June.

    Gray makes this species a variety of P. monspeliensis:

    POTENTILLA L. CINQUEFOIL. FIVE-FINGER
    Calyx flat, deeply 5-cleft, with as many bractlets at the sinuses, thus appearing 10-cleft. Petals 5, usually roundish. Stamens many. Achenes many, collected in a head on the dry mostly pubescent or hairy receptacle; styles lateral or terminal, deciduous. Radicle superior. Herbs, or rarely shrubs, with com- pound leaves, and solitary or cymose flowers; their parts rarely in fours. (Name diminutive from potens, powerful, originally applied to P. Anserina, from its reputed medicinal powers.)

    P. monspeliensis L. Stout, erect, hirsute, 2-1) dm. high ; leaves 3-foliolate; leaflets obovate to oblanceolate, those of the uppermost leaves toothed nearly the whole length ; cyme rather close, leafy; calyx large; stamens 15-20. Open soil, Nfd. to Alaska, s. to D. C., Mo., Kan., and N. Mex. May-Aug. (E. Asia.)

    Var. norvegica (L.) Rydb. Less hirsute; leaflets more narrowly oblong, those of the uppermost leaves mostly 3-5-toothed near the end; inflorescence looser. (P. norvegica L.) Similar situations, e. Que. to n. N. E., L. Superior, and northwestw.; occasional on ballast southw. (Eurasia.)

  • Mouse-Ear Chickweed (Cerastium fontanum)

    A pretty little flower when we magnify it like this, Chickweed is one of those low lawn-dwellers that suburban homeowners abhor. If your lawn simply must be made up of uniform blades of grass snipped to a precisely even height, then chickweed is your enemy. Otherwise, it does little harm, and cheers us up with starry little flowers that reward a close look, giving us an incentive to get better acquainted with the natural world of our own front yards. This patch grew in a side yard in Beechview, where it was blooming in the middle of June.

    Gray describes the genus and the species, which he lists as C. vulgatum:

    CERASTIUM L. MOUSE-EAR CHICKWEED
    Sepals 5, rarely 4. Petals as many, 2-lobed or -cleft, rarely entire, often wanting in some of the flowers. Stamens 10 or fewer. Styles mostly 5, rarely 4 or 3, opposite the sepals. Pod 1-celled, usually elongated, -often 1 Curved, membranaceous, opening at the summit by twice as many teeth as there were styles, many-seeded. Seeds rough. (Name from Keras, a horn, alluding the shape of the pod.)

    C. vulgatum L. (COMMON M.) Stems clammy-hairy, spreading (1.5-4 dm. long); leaves chiefly oblong (varying to spatulate and ovate-lanceolate); upper bracts nearly herbaceous; flowers at first clustered; sepals 4-6 mm. long, obtusish; pedicels longer, the fruiting ones much longer than the -calyx. (C. viscosum of the Linnean herbarium; C. triviale Link.) Fields, dooryards, etc.; common. May-July. (Nat. from Eu.)

  • Common Milkweed (Asclepias syriaca)

    This distinctively odd-looking plant is a common sight along the road or at the edges of field; this one grew at the edge of an old German cemetery in Beechview, where it was blooming in late June. The plants stand straight and tall; the flowers form almost umbels in almost perfect spheres. From a distance their color resembles the color that used to be called “flesh” in children’s crayon boxes, until the manufacturers discovered that  no healthy human actually has flesh that color. The strong scent is irresistible to butterflies.

    Milkweeds and their allies were traditionally placed in the Milkweed family, Asclepiaceae; but modern botanists make that family a subfamily (Asclepiadoideae) of the Dogbane family, Apocynaceae. The species name syriacus comes from a pre-Linnaean botanist who confused this species with one from the Near East.

    Gray describes the genus and the species:

    ASCLEPIAS [Tourn.] L. MILKWEED. SILKWEED
    Calyx persistent ; divisions small, reflexed. Corolla deeply 5-parted; divisions valvate in bud, deciduous. Crown of 5 hooded bodies seated on the tube of stamens, each containing an incurved horn. Stamens 5, inserted on the base of the corolla; filaments united into a tube which incloses the pistil; anthers adherent to the stigma, each with 2 vertical cells, tipped with a membranaeeons appendage, each cell containing a flattened pear-shaped and waxy pollen-mass; the two contiguous pollen-masses of adjacent anthers, forming pairs which hang by a slender prolongation of their summits from 5 cloven glands tbat grow on the angles of the stigma (extricated from the cells by insects, and directing copious pollen-tubes into the point where the stigma joins the apex of the style). Ovaries 2, tapering into very short styles; the large depressed 5-angled fleshy stigmatic disk common to the two. Follicles 2, one of them often abortive, soft, ovoid or lanceolate. Seeds anatropous, flat, margined, bearing a tuft of long silky hairs (coma) at the hilum, downwardly imbricated all over the large placenta, which separates from the suture at maturity. Embryo large, with broad foliaceous cotyledons in thin albumen. Perennial herbs; peduncles terminal or lateral and between the usually opposite petioles, bearing simple many-flowered umbels, in summer. (The Greek name of Aesculapius, to whom the genus is dedicated.)

    A. syriaca L. (COMMON M. or SILKWEED.) Stem tall and stout, finely soft-pubescent; leaves lance-oblong to broadly oval, 1-2 dm. long, pale, minutely downy beneath, as well as the peduncles, etc. ; corolla-lobes dull purple to white, 6-9 mm. long; hoods rather longer than the anthers, ovate, obtuse, with a tooth each side of the short stout claw-like horn. (A. Cornuti Dene.) Rich ground, N. B. to Sask., and southw. June-Aug. Intermediates, perhaps of hybrid origin, occur between this and some of the related species.