Flora Pittsburghensis

Author: Father Pitt

  • Field Pennycress (Thlaspi arvense)

    An unimposing little weed, but it delights children by producing round, flat seedpods that look like coins. This one grew in a meadow near Cranberry, where it was blooming and already seeding in the middle of June.

    Gray describes the genus and the species:

    THLASPI [Tourn.] L. PENNY CRESS
    Pod orbicular, obovate, or obcordate, flattened contrary to the narrow partition, the midrib or keel of the boat-shaped valves extended into a wing. Seeds 2-8 in each cell. Cotyledons accumbent. Petals equal.—Low plants, with root-leaves undivided, stem-leaves arrow-shaped and clasping, and small white or purplish flowers. (Name from thlaein, to crush, from the flattened pod.)

    T. arvense L. (FIELD P. or MITHRIDATE MUSTARD.) Smooth annual; lower leaves wing-petioled, the upper sagittate-clasping; broadly winged pod 1.2 cm. in diameter, deeply notched at top; style minute. Waste places; not common, except along our northern borders, where too abundant and called “FRENCHWEED.” (Nat. from Eu.)

  • Long-Leaved Starwort (Stellaria longifolia)

    Also called Long-Leaved Stitchwort, this is a remarkably delicate little plant whose ethereally insubstantial stems and leaves make it seem as though the starry little flowers are floating in the air. It likes an overgrown meadow; this one was growing among clovers and cinquefoils in a meadow near Cranberry, where it was blooming in the middle of June.

    A good description from Mathews’ Field  Book of North American Wild Flowers:

    A tall very slender species with many branches, the stem with rough angles, and the light green leaves small and lance-shaped. The tiny flowers like white stars, with five white petals so deeply cleft that they appear as ten, sepals nearly equalling the petals in length. 10-20 inches high. In wet grassy places everywhere.

    Gray describes the genus and the species:

    STELLARIA L. CHICKWEED. STARWORT
    Sepals 4-5. Petals (white) 4-5, deeply 2-cleft, sometimes none. Stamens 8, 10, or fewer. Styles 3, rarely 4 or 5, opposite as many sepals. Pod ovoid, 1-celled, opening by twice as many valves as there are styles, several-many-seeded. Seeds naked. Flowers solitary or cymose, terminal or appearing lateral by the prolongation of the stem from the upper axils. (Name from stella, a star, in allusion to the star-shaped flowers.) ALSINE. in part, not Wahlenb.

    S. longifolia Muhl. Stem erect, weak, often with rough angles (2-5 dm. high); leaves linear, acutish at both ends, spreading; cymes scaly-bracted, at length lateral, peduncled, many-flowered, the slender pedicels spreading or deflexed; fruit pale straw-colored; seeds smooth. (Alsine Britton.)—Grassy places, Nfd. to Md., and westw. June, July. (Eu.)


  • Alsike Clover (Trifolium hybridum)

    Red Clover (T. pratense) is more common and very similar, and grows in most of the same places. The best way to tell the difference is by the leaves, which in Red Clover usually (but not always) show a chevron pattern but are unmarked in Alsike Clover; and by the color of the flowers, which in Alsike Clover is less magenta and more pale rosy pink, with young white flowers in the center of the head. In fact, it does look like something halfway between Red Clover and White Clover (T. repens), which may account for the specific name hybridus for a plant that is not a hybrid.

    This plant grew in a meadow near Cranberry, where it was blooming in the middle of June.

    Gray describes the genus and the species:

    TRIFOLIUM [Tourn.] L. CLOVER. TREFOIL

    Calyx persistent, 5-cleft, the teeth usually bristle-form. Corolla mostly withering or persistent; the claws of all the petals, or of all except the oblong or ovate standard, more or less united below with the stamen-tube; keel short and obtuse. Tenth stamen more or less separate. Pods small and membranous, often included in the calyx, 1-6-seeded, indehiscent, or opening by one of the sutures. Tufted or diffuse herbs. Leaves mostly palmately (sometimes pinnately) 3-foliolate; leaflets usually toothed. Stipules united with the petiole. Flowers in heads or spikes. (Name from tres, three, and folium, a leaf.)

    T. HYBRIDUM L. (ALSIKE C.) Resembling T. repens, but the stems erect or ascending, not rooting at the nodes; leaflets ovate, rounded at apex; flowers rose-tinted. Generally common. (Introd. from Eu.)

  • St. John’s Wort (Hypericum perforatum)

    These cheerful flowers love to grow in the poorest soil; this plant grew on an eroded clay bank near Cranberry, where it was blooming in the middle of June. The thick wad of stamens in the middle of the flower is characteristic of St. John’s Worts, most of which also have bright yellow flowers.

    Gray describes the genus and the species:

    HYPERICUM [Tourn.] L. ST. JOHN’S-WORT
    Sepals 5, usually subequal. Petals 5, oblique, convolute in the bud (except in 6). Stamens frequently united or clustered in 3-5 parcels; no interposed glands. Pod 1-celled or 3-5-celled. Seeds usually cylindrical. Herbs or shrubs, with cymose yellow, flesh-colored, or purplish flowers. (An ancient Greek name of obscure meaning.)

    H. perforatum L. (COMMONS.) Stem much branched and corymbed, somewhat 2-edged, producing runners from the base; leaves elliptic- or linear-oblong, with pellucid dots; petals deep yellow, black-dotted along the margin, twice the length of the lanceolate acute sepals; flowers numerous, in open leafy cymes. Fields, etc. June-Sept. A pernicious weed, difficult to extirpate; juice very acrid. (Nat. from Eu.)

  • Everlasting Pea (Lathyrus latifolius)

    Everlasting Pea is a vigorous vine that can take over whole hillsides. It compensates us for the space it takes with a glorious array of flowers in shades from white through deep magenta, often (as here) with stripes or bicolor patterns.

    Gray describes the genus and the species:

    LATHYRUS [Tourn.] L. VETCHLING. EVERLASTING PEA

    Style dilated and flattish (not grooved) above, hairy along the inner side (next the free stamen). Sheath of the filaments scarcely oblique at the apex. Otherwise nearly as in Vicia. Our species perennial and mostly smooth plants. (Lathyros, a leguminous plant of Theophrastus.)

    L. latifolius L. (EVERLASTING or PERENNIAL PEA.) Tall perennial with broadly winged stems; leaves and stipules coriaceous and veiny; petioles mostly winged; the 2 elliptic to lanceolate leaflets 0.5-1 dm. long; peduncles stiff, many-flowered; flowers showy, pink, purple, or white. Frequently cultivated, and escaping to roadsides and thickets, Ct. to 1). C. (Introd. from Eu.)

    Another picture is here.