Wild Flowers of Pittsburgh

Cruciferae

Dame’s Rocket (Hesperis matronalis)

Pittsburghers usually call it “phlox,” or—as we have heard a Pittsburgher say—“some sort of phlock.” 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. 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. The flowers in these pictures were blooming in late May; the solid colors were in Mount Lebanon, and the bicolors in Beechview.

The pictures in this particular article have been donated to Wikimedia Commons under the Creative Commons CC0 1.0 Universal Public Domain Dedication. No permission is needed to use them for any purpose.

Gray describes the genus and the species:

HESPERIS [Tourn.] L. ROCKET. 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.)


Spring Cress (Cardamine bulbosa)

Cardamine-bulbosa-2013-05-03-Bird-Park-01A relative of the Toothworts (which most botanists now also place in the genus Cardamine), this pretty little flower seems to like damp locations. This one was growing in a damp open woods in Bird Park in Mount Lebanon, where it was blooming in early May. The round leaves (changing to long and narrow as they go up the stem) distinguish this from other common species of Cardamine in our area.

Gray describes the genus and the species:

CARDÂMINE [Tourn.] L. BITTER CRESS. Pod linear, flattened, usually opening elastically from the base; the valves nerveless and veinless, or nearly so; placentae and partition thick. Seeds in a single row in each cell, wingless; the funiculus slender. Cotyledons aecumbent, flattened, equal or nearly so, petiolate.— Mostly glabrous perennials, leafy-stemmed, growing along watercourses and in wet places. Flowers white or purple. (A Greek name, used by Dioscorides for some cress, from its cordial or cardiacal qualities.)

Simple-leaved perennials with tuberous base.

С. bulbosa (Srhreb.) BSP. (SPRING CRESS.) Stems upright from a tuberous base and slender rootstock bearing small tubers, simple, or rarely forking, glabrous, in anthesis 1-1.5 dm. high; root-leaves oblong to cordate-ovate, stem-leaves 5-8, scattered, the lower ovate or oblong and somewhat petioled, the upper sessile, almost lanceolate, all often toothed; sepals greenish, with white margin; petals white, 7-12 mm. long; pods linear-lanceolate, pointed with a slender style tipped by a conspicuous stigma; seeds oval. (C. rhomboidea DC.) — Wet meadows and springs, e. Mass. to Minn., and southw. May, .June.


Hairy Bittercress (Cardamine hirsuta)

Depending on your point of view, this is either an invasive weed or a cheery harbinger of spring. It comes from Europe, and it makes itself at home in our lawns, where it politely refuses to exceed the height of the grass around it. There are people who eat it as a salad herb, so it can’t be all bad. It’s one of the first things to bloom in the spring, appearing along with the crocuses and persisting through daffodil season. This patch was blooming in a lawn in Beechview in early April.

Gray describes the genus and the species:

CARDÂMINE [Tourn.] L. Bitter Cress. Pod linear, flattened, usually opening elastically from the base; the valves nerveless and veinlees, or nearly so; placentae and partition thick. Seeds in a single row in each cell, wingless; the funiculus slender. Cotyledons accumbent, flattened, equal or nearly so, petiolate.— Mostly glabrous perennials, leafy-stemmed, growing along watercourses and in wet places. Flowers white or purple. (A Greek name, used by Dioscorides for some cress, from its cordial or cardiacal qualities.)

Root mostly biennial or annual; leaves pinnately 5-11-foliolate, flowers small, white.

Stamens 4; leaflets strigose-hispid upon the upper surface.

С. hirsuta L. Leaves chiefly radical, with short and broad leaflets, but those on the erect stem reduced and with narrow leaflets; pods erect, on ascending or appressed pedicels. — Moist places, s. l’a. to N. C, and “Mich.” (Eu.) Perhaps introduced. A doubtful specimen from w. Mass. (Miss Vail).


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.)


Charlock (Brassica arvensis)

Now known as Sinapis arvensis; also formerly called Brassica kaber. A common weed along roadsides and in fields. The larger flowers easily distinguish it from the other wlid mustards.

Gray describes the genus and the species:

BRASSICA [Tourn.] L. MUSTARD. TURNIP
Annuals or biennials, with yellow flowers. Lower leaves mostly lyrate, incised, or pinnatifid. (The Latin name of the Cabbage.)

B. ARVENSIS (L.) Ktze. (CHARLOCK.) Knotty pods fully one third occupied by a stout 2-cdged beak; upper leaves rhombic, scarcely petioled, merely toothed; fruiting pedicels short, thick; pods smooth or rarely bristly. 4 cm. long. (B. Sinapistrum Boiss.; Sinapis arvensis L.) Noxious weed in grainfields, etc. (Nat. from Eu.)


Toothwort (Cardamine concatenata)

Cut-Leaf Toothworts are common in rich open woods; this one was blooming on a wooded hillside in Mount Lebanon in late April. The leaves are distinctive: they grow in whorls of three, and they are narrow and deeply divided, with jagged teeth on each lobe. The flowers of Broadleaf Toothwort (Cardamine diphylla) are similar, but the leaves are very different.

Gray puts the Toothworts in the genus Dentaria, and lists this one as Dentaria laciniata.

DENTARIA [Tourn.] L. TOOTHWORT. PEPPER-ROOT
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; stems 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. laciniata Muhl. Tubers deep-seated; stems pubescent above; cauline leaves 3, whorled or nearly so, the lateral leaflets deeply cleft, glabrous or pubescent, the segments linear to narrowly oblong, conspicuously gash-toothed; basal leaves, when present, similar; flowers white or purplish; calyx 6-9 mm. long; petals 1-2 cm. long. Rich damp woods, w. Que. and Vt. to Minn., and southw. Apr., early May.


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:

HESPERIS [Tourn.] L. ROCKET
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:

DENTARIA [Tourn.] L. TOOTHWORT. PEPPER-ROOT
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)

Nasturtium-officinale-2009-10-22-Wexford-01

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:

RADICULA [Dill.] Hill. WATER CRESS
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)

Lobularia-maritima-01

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:

LOBULARIA Desv. SWEET ALYSSUM

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.)


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