Flora Pittsburghensis

Author: Father Pitt

  • Peppermint (Mentha × piperita)

    Peppermint is apparently a hybrid between Spearmint (Mentha spicata) and Watermint (Mentha aquatica). If nothing else, the scent and flavor of the leaves are enough to identify the plant. It shows a strong preference for damp locations, although it will grow almost anywhere you plant it. It seldom produces viable seed, but it nevertheless makes a nuisance of itself in some parts of the country. Around here it is only an occasional tasty volunteer. This colony was growing in a wet depression beside a tributary of Wexford Run, where it was blooming in early September.

    Linnaeus described this plant as a species, M. piperita; the × in Mentha × piperita denotes that the universal judgment of modern botanists identifies it as a hybrid. Gray’s description:

    MÉNTHA [Tourn.] L. MINT. Calyx Ьеll-shaped or tubular, the 5 teeth equal or nearly so. Corolla with a short included tube, the upper lobe slightly broader, entire or notched. Stamens 4, equal, erect, distant. — Odorous perennial herbs; the small flowers mostly in close clusters, forming axillary capitate whorls, sometimes approximated in interrupted spikes, produced in summer, of two sorts as to the fertility of the stamens in most species. Corolla pale purple or whitish. Species mostly adventive or naturalized from Europe, with many hybrids. (Minthe of Theophrastus, from a Nymph of that name, fabled to have been changed Into Mint by Proserpine.)

    M. piperìta L. (PEPPERMINT.) Glabrous, very pungent-tasted; leaves ovate-oblong to oblong-lanceolate, acute, sharply serrate; spikes becoming loose; calyx glabrous below, the teeth hirsute. — Along brooks, frequent. (Nat. from Eu.)

  • Dodder (Cuscuta gronovii)

    A curious parasitic member of the Morning-Glory family. Dodder has no green coloring of its own because it has no chlorophyll; instead, a seedling must, within a few days of sprouting, attach itself to a suitable host plant, and begin to rob it of its sap.

    There are many species of Dodder around the world, but this one is (as far as we know) the only one found in the Pittsburgh area, which makes it hard to misidentify. The stringy orange stems and the unearthly waxy flower clusters are unique. These vines were blooming along a tributary of Wexford Run in early September.

    The genus Cuscuta usually makes its home in the family Convolvulaceae, the Morning-Glory Family; but it sometimes runs away from home and attempts to establish a household for itself as the family Cuscutaceae. Right now the botanical consensus seems to place it in Convolvulaceae.

    Gray describes the genus and the species:

    CÚSCUTA [Tourn.] L. DODDER. LOVE-VINE.

    Calyx 5(rarely 4)-cleft, or of 5 sepals. Corolla globular-urn-ehaped, bellshaped, or short-tubular, the spreading border 5(rarely 4)-cleft, imbricate. Stamens with a scale-like often fringed appendage at base. Ovary 2-celled, 4-ovuled; styles distinct, or rarely united. Capsule mostly 4-seeded. Embryo spirally coiled in the rather fleshy albumen, sometimes with a few alternate scales (belonging to the plumule); germination occurring in the soil. — Leafless annual herbs, with thread-like yellowish or reddish stems, bearing a few minute scales in place of leaves; on rising from the ground becoming entirely parasitic on the bark of herbs and shrubs on which they twine, and to which they adhere by means of suckers developed on the surface in contact. Flowers small, cymose-clustered, mostly white, usually produced in summer and autumn. (Name supposed to be of Arabic derivation.)

    Calyx gamosepalous; ovary and capsule pointed, the latter enveloped or capped by the marcescent corolla; flowers in loose panicled cymes.

    Corolla-lobes obtuse, spreading.

    C. gronòvii Willd. Stems coarse, often climbing high; corolla-lobes shorter than or equaling the deeply campanulate tube; scales copiously fringed; capsule globose, umbonate.— Wet shady places, N. S. to Man., and southw. — The commonest of our species. Very variable in size and compactness of clusters.

  • Giant Ragweed (Ambrosia trifida)

    A heaping helping of ragweed, easily growing to 9 feet (3 m) if it likes the location (Gray says to 6 m or 18 feet), and letting loose a raging torrent of allergenic pollen in early September, as these plants in Beechview were doing. The harmless and beautiful goldenrods that bloom at the same time often take the blame for hay fever, but this huge yet somehow inconspicuous weed, and its even more common little cousin A. artemisiifolia, are the real culprits. These plants appear to be what Gray describes as the variety integrifolia: the leaves are mostly three-lobed, except for a few unlobed lanceolate leaves up near the flowers.

    The generic name Ambrosia, from the Greek word for “immortal,” probably means that, as weeds go, these things are hard to kill. It was probably not intended to suggest that the Olympian gods supped on ragweed.

    Gray describes the genus and the species:

    AMBRÒSIA [Tourn.] L. RAGWEED. Fertile heads 1-3 together, sessile in axils of leaves or bracts, at the base of racemes or spikes of sterile heads, Merile involucres flattish or top-shaped, of 7-12 united bracts, containing 6-20 staminate flowers, with or without slender chaff intermixed. Anthers almost separate. Fertile involucre (fruit) ellipsoid, obovoid, or top-shaped, closed, pointed, resembling an achene and inclosing a single flower; elongated style-branches protruding. Achenes ovoid. — Coarse homely weeds, with opposite or alternate lobed or dissected leaves, and inconspicuous greenish flowers, in late summer and autumn; ours annuals, except the last. (The Greek and later Latin name of several plants, as well as of the food of the gods.)

    Sterile heads in single or panicled racemes or spites, the involucre regular.

    Leaves opposite, only once lobed; sterile involucre 3-ribbed on one side.

    A. trífida L. (GREAT R.) Stem stout, 1-6 m. high, rough-hairy, as are the large deeply 3-lobed leaves, the lobes oval-lanceolate and serrate; petioles margined; fruit obovoid, 5-6-ribbed and tubercled. — Rich soil, common westw. and southw., much less so northeastw. Var. integrifòlia (Muhl.) T. & G. Smaller, with the upper leaves (or all of them) undivided, ovate or oval.—Same habitat, not rare.

  • Orange Touch-Me-Not (Impatiens capensis)

    Also called Spotted Touch-Me-Not or Jewelweed. Very similar to the Yellow or Pale Touch-Me Not (I. pallida), and often found in the same colony. Most of the differences are subtle; I. capensis tends to have smaller, darker leaves, often with a noticeable bluish tinge. The flowers, however, leave no doubt about the species: the bright orange of I. capensis is instantly obvious. Since the flowers bloom from late June to the first frost, we can rely on them to identify the plant. These were blooming at the edge of a field near Cranberry in late August.

    The specific name capensis is unfortunate. The botanist who named it thought the specimen came from the Cape Colony in Africa. The names Impatiens fulva and I. biflora were current for much of the nineteenth and twentieth centuries; but the inflexible rule of priority has asserted the rights of the name capensis, however wrongheaded it may be.

    Gray describes the genus and the species:

    IMPATIENS [Rivinius] L. BALSAM, JEWELWEED. Sepals apparently only 4; the anterior one notched at the apex (probably two combined); the posterior one (appearing anterior as the flower hangs on its stalk) largest, and forming a usually spurred sac. Petals 2, 2-lobed (each a pair united). Filaments appendaged with a scale on the inner side, the б scales connivent over the stigma; anthers introrse. Pod with evanescent partitions, and a thick axis bearing several anatropous seeds; valves 6, coiling elastically and projecting the seeds in dehiscence. — Leaves in ours ovate or oval, coarsely toothed, petioled. Flowers axillary or panicled, often of two sorts, viz., the larger ones which seldom ripen seeds; and very small ones which are fertilized early in the bud, their floral envelopes never expanding but forced off by the growing pod and carried upward on its apex. (Name from the sudden bursting of the pods when touched, whence also the popular appellation.)

    I. biflora Walt. (SPOTTED TOUCH-ME-NOT.) Flowers orange-color, thickly spotted with reddish brown; sac longer than broad, acutely conical, tapering into a strongly inflexed spur half as long as the sac. (I. fulva Nutt) — Rills and shady moist places. June-Sept. —Plant 6-8 dm. nigh. Forms with spotless, whitish, or roseate flowers have been found.

  • Yellow Touch-Me-Not (Impatiens pallida)

    Also called Pale Touch-Me-Not or Jewelweed. The name “Touch-Me-Not” comes from the explosive seedpods, which give no end of entertainment to children and any adults who are not beyond being entertained by natural amusements. The pods have parallel ribs connected by a thin membrane, and the membrane gets thinner and weaker as the pod ripens. At length the membrane can be ruptured by the slightest touch, and then the ribs instantly coil into springs, sending seeds flying in all directions.

    These plants are close relatives of the garden Impatiens, which have similarly explosive seedpods. All Impatiens species have thick, juicy stems, and large colonies of them will form dense, even mounds.

    We have two species of Touch-Me-Not in the area. Yellow Touch-Me-Not is more common in the north and at higher elevations; Orange or Spotted Touch-Me-Not (I. capensis) is more common in the south and at lower elevations. Pittsburgh is right where the ranges meet, so we get both, often in the same colony. The yellow species is more common here, but the orange is also very common, especially in lower areas.

    The juice from the thick stems is supposed to be a good preventative for poison ivy if rubbed on the affected parts soon after exposure.

    Gray describes the genus and the species:

    IMPATIENS [Rivinius] L. BALSAM, JEWELWEED. Sepals apparently only 4; the anterior one notched at the apex (probably two combined); the posterior one (appearing anterior as the flower hangs on its stalk) largest, and forming a usually spurred sac. Petals 2, 2-lobed (each a pair united). Filaments appendaged with a scale on the inner side, the б scales connivent over the stigma; anthers introrse. Pod with evanescent partitions, and a thick axis bearing several anatropous seeds; valves 6, coiling elastically and projecting the seeds in dehiscence. — Leaves in ours ovate or oval, coarsely toothed, petioled. Flowers axillary or panicled, often of two sorts, viz., the larger ones which seldom ripen seeds; and very small ones which are fertilized early in the bud, their floral envelopes never expanding but forced off by the growing pod and carried upward on its apex. (Name from the sudden bursting of the pods when touched, whence also the popular appellation.)

    I. pallida Nutt. (PALE TOUCH-ME-NOT.) F’lowers pale-yellow, sparingly dotted with brownish-red; sac dilated and very obtuse, broader than long, tipped with a short incurved spur. (I. aurea Muhl. ?) — Moist shady places and along rills, in rich soil, n. Me. and w. N. E., westw. and southw. July-Sept. — Larger and greener than the next [I. capensis], with larger flowers. A form with unspotted flowers occurs.