Category: Cruciferae

  • Dame’s Rocket (Hesperis matronalis)

    Pittsburghers usualy call it “phlox,” but this ubiquitous late-spring flower is really a member of the mustard or crucifer family, as you can tell by the four-petaled flowers (real Phlox flowers have five petals). It came from Europe as a garden flower and quickly made itself at home. It would be hard to conjure up any inhospitable feelings toward this welcome guest, whose bright flowers decorate roadsides and back yards everywhere (these flowers were blooming in Mount Lebanon in late May). Each colony blooms in a mixture of colors from deep magenta to white, and many plants grow flowers with splashes or stripes of contrasting colors.

    Gray describes the genus and the species:

    Pod linear, nearly cylindrical; stigma lobed, erect. Seeds in 1 row in each cell, oblong, marginless. Cotyledons incumbent. Biennial or perennial, with serrate sessile or petiolate leaves, and large purple flowers. (Name from hespera, evening, from the evening fragrance of the flowers.)

    H. MATRONALIS L. (DAME’S VIOLET.) Tall: leaves lanceolate, acuminate; pods 5-10 cm. long, spreading. Sometimes cultivated, and spreading to roadsides, etc. (Introd. from Eu.)

  • Broadleaf Toothwort (Cardamine diphylla)

    Not as common around here as its close relative the Cutleaf Toothwort (Cardamine concatenata), this plant grows on the same wooded hillsides, especially in stream valleys. It’s easily distinguished by its two leaves with three broad leaflets each (C. concatenata has three leaves with very narrow lobes). This plant was blooming in early May near the Trillium Trail in Fox Chapel.

    Gray lists this as Dentaria diphylla. He describes the genus and the species thus:

    Pod lanceolate, flat. Style elongated. Seeds in one row, wingless, the funiculus broad and flat. Cotyledons petioled, thick, very unequal, their margins somewhat infolding each other. —Perennials, of damp woodlands, with long fleshy sometimes interrupted scaly or toothed rootstocks, of a pleasant pungent taste; steins leafless below, bearing 2 or 3 petioled compound leaves about or above the middle, and terminated by a corymb or short raceme of large white or purple flowers. (Name from dens, a tooth.)

    D. diphylla Michx. Rootstock long and continuous, often branched, the annual segments slightly or not at all tapering at the ends; stems in anthesis 1.5-3 dm. high, stoutish; leaves 3-foliolate, the basal and cauline similar, the latter 2 (rarely 3), opposite or subopposite, leaflets 4-10 cm. long, short-petiolulate, rhombic-ovate or oblong-ovate, coarsely crenate, the teeth bluntly mucronate; flowers white; sepals 5-8 mm. long, half the length of the petals; pods rarely maturing. Rich woods and thickets, e. Que. to s. Ont. and Minn., s. to S.C. and Ky. Apr., May. Rootstocks 2-3 dm. long, crisp, tasting like Water Cress.

  • Watercress (Nasturtium officinale)


    Watercress likes to grow with its feet in the edge of a lazy stream. This colony grew in a little tributary of the Pine Creek in Wexford, where it was blooming profusely in late October. The main blooming season is in the spring, but the cool weather of fall seems to give the plants their second wind.

    Gray lists the plant as Radicula nasturtium-aquaticum:

    Pod a short silique or a silicle, varying from slender to globular, terete or nearly so; valves strongly convex, nerveless. Seeds usually numerous, small, turgid, marginless, in 2 irregular rows in each cell (except in R. sylvestris).  Cotyledons accumbent. Aquatic or marsh plants, with yellow or white flowers, and commonly pinnate or pinnatifid leaves, usually glabrous. (Name meaning a little radish.)  RORIPA Scop.   NASTURTIUM R. Br.

    1. Petals white, twice the length of the calyx, pods linear; leaves pinnate.

    R. NASTURTIUM-AQUATICUM (L.) Britten & Rendle. (TRUE W.) Perennial; stems spreading and rooting; leaflets 3-11, roundish or oblong, nearly entire; pods (1.2-1.6 cm. long) ascending on slender widely spreading pedicels. (Sisymbrium L.; Nasturtium officinale R. Br.; Roripa Nasturtium Rusby.)—Brooks, ditches, etc., originally cultivated. (Nat. from Eu.)

  • Sweet Alyssum (Lobularia maritima)


    A popular bedding plant that liberally seeds itself. When seeds get washed downhill, they lodge in sidewalk cracks, where they’re quite happy to grow and bloom all summer and well into fall, producing more seeds to lodge in sidewalk cracks, and making the garden Alyssum one of our more common urban weeds. This plant grew where the sidewalk met a stone retaining wall in Beechview.

    From Gray’s Manual:


    Pod small, orbicular, with only one or two wingless seeds in a cell; valves nerveless, somewhat convex, the margin flattened. Petals white, entire. Cotyledons accumbent. Hairs of the stem and leaves 2-pointed, appressed, attached in the middle. (Latin lobulus, a little lobe, probably referring to the 2-lobed hairs. )

    1. L. MARITIMA (L.) Desv. Slightly hoary; leaves linear; flowers small, honey-scented. (Alyssum Lam.; Koniga R. Br.) Often cultivated, and occasionally spontaneous. (Introd. from Eu.)