Wild Flowers of Pittsburgh


Ground Ivy (Glechoma hederacea)

Ground Ivy, Creeping Charlie, or Gill-Over-the-Ground, is a foreign invader, and for grass purists it’s a hated broadleaf weed. It is, however, easy to get along with. It smells minty fresh when you mow it, and it produces these stunningly beautiful flowers in the spring. This colony was growing in a lawn in Mount Lebanon, where it was blooming in late May.

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 places this in the genus Nepeta:

NEPETA L. CAT MINT. Calyx tubular, often incurved. Corolla dilated in the throat; the upper lip erect, rather concave, notched or 2-cleft; the lower 3-cleft, the middle lobe largest, either 2-lobed or entire. —Perennial herbs. (The Latin name, thought to be derived from Nepete, an Etruscan city.)

N. hederacea (L.) Trevisan. (GROUND IVY, GILL-OVER-THE-GROUND.) Creeping and trailing; leaves petioled, round-kidney-shaped, crenate, green both sides; corolla thrice the length of the calyx, light blue. (Glecoma L.; Glechoma Benth.) Damp or shady places, near towns—May-July. (Nat. from Eu.)

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.)

Bluets (Houstonia caerulea)


KONICA MINOLTA DIGITAL CAMERAAlso known as Quaker Ladies, these tiny blue flowers form tidy clumps in shaded lawns and roadsides. Small as the delightful four-petaled flowers are, they rise from a plant that seems tiny out of all proportion to the flowers. These were blooming in late May (a little late this year) in Frick Park.

Gray describes the genus and the species:

HOUSTÔNIA L. Calyx 4-lobed, persistent; the lobes in fruit distant. Corolla usually much longer than the calyx-lobes, the lobes valvate in the bud. Anthers linear or oblong. Style 1; stigmas 2. Ovary 2-celled. Pod top-shaped, globular, or didymous, thin, its summit or upper half free from and projecting beyond the tube of the calyx, loculicidal across the top. Seeds 4-20 in each cell, pitted. — Small herbs, with short entire stipules connecting the petioles or narrowed bases of the leaves, and cymose or solitary and peduncled flowers; these dimorphous, in some individuals with exserted anthers and short included style; in others the anthers included and the style long, the stigmas therefore protruding. (Named for Dr. William Houston, an English botanist, who collected in tropical America.)

Small and delicate, vernal-flowering; peduncles 1-flowered; corolla salverform; upper half of the broad and someirhat 2-lobed pod free; seeds globular, with a very deep round cavity occupyiny the inner face.

Perennial by delicate filiform creeping rootstocks or creeping stems; peduncles filiform, 2-5 cm. long.

H. caerulea L. (BLUETS, INNOCENCE.) Glabrous; stems erect, slender, sparingly branched from the base, 0.5-2 dm. high; lrares oblong-spatulate,6-9 mm. long; peduncle filiform, erect; corolla light blue, pale lilac or nearly white, with a yellowish eye, the straight slender long-exserted tube much longer than its lobes or than those of the calyx. — Moist and grassy places, N. S. to Ga., w. to Ont., Wise, and Ala.; producing from early spring to midsummer its delicate little flowers.


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