Wild Flowers of Pittsburgh

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Boston Ivy (Parthenocissus tricuspidata)


Parthenocissus-tricuspidata-2013-10-17-Oakland-01A member of the grape family and a very close relative of Virginia Creeper, Boston Ivy bears these beautiful (but poisonous) berries. Its flowers are tiny and insignificant. The leaves are the main attraction; they are usually very similar to grape leaves, but occasionally divided into three leaflets.

Parthenocissus tricuspidata is an Asian import; it is not listed, except in passing, in any of our standard botanical references, but it is plentifully naturalized in the city of Pittsburgh and inner suburbs. According to the USDA PLANTS database, it is unknown in the wild in our area outside Allegheny County.

These vines sprawled over a chain-link fence in the back streets of Oakland, where they were blooming and fruiting in the middle of October.

Purslane (Portulaca oleracea)


This tiny prostrate weed is a close relative of the colorful Moss Roses we grow in gardens—the thick, fleshy red stems and succulent leaves show the relationship clearly. The little yellow flowers open only in the morning, and only in bright sunlight; we shaded the plants momentarily to take these pictures at midday without the harsh glare. Purslanes can grow almost anywhere they get a foothold, and can survive being pulled up and thrown away to root elsewhere. In the city they are very common crack-in-the-sidewalk weeds. The plant above was growing from a crack on the top of a low concrete wall; the one below (magnified many times—the boulders in the picture are ordinary gravel) was growing in a gravel parking lot. Both were a little west of Cranberry, blooming in early September. Purslane was once commonly used as a salad green, valued for its texture rather than its famously bland taste.


We are experimenting with a camera we bought used for $20 that claims to be able to focus as close as an inch from the subject. So far, we are pleased with the results.

Gray describes the genus and the species:

PORTULACA [Tourn.] L.  PURSLANE. Calyx 2-cleft; the tube cohering with the ovary below. Petals 5, rarely 6, inserted on the calyx with the 7-20 stamens, fugacious. Style mostly 3-8-parted. Pod 1-celled, globular, many-seeded, opening transversely, the upper part (with the upper part of the calyx) separating as a lid. — Fleshy annuals, with mostly scattered leaves. (An old Latin name, of unknown meaning.)

P. olerácea L. (COMMON P.) Prostrate, very smooth; leaves obovate or wedge-form ; flowers sessile (opening only in sunny mornings); sepals keeled; petals pale yellow; stamens 7-12 ; style deeply 5-6-parted; flower-bud flat and acute. — Cultivated and waste grounds; common.—Seemingly indigenous westw. and southwestw. (Nat. from Eu.)

Orange Hawkweed (Hieracium aurantiacum)

Hieracium-aurantiacum-2013-09-02-Fox-Chapel-02Until today we had not found this plant in the city of Pittsburgh, though it is ubiquitous north of a line that roughly bisects Pennsylvania from east to west. This plant, however, was one of a number growing in a lawn in Highland Park, where it was blooming at the beginning of September.

There is no mistaking this plant for anything else. There are many flowers that look like small dandelions, but only one is bright orange—a rare color among flowers, otherwise represented here mostly by Daylilies and Orange Touch-Me-Nots.

We had previously collected a picture of this species from Crawford County, and we repeat our remarks:

Also called “Devil’s Paintbrush,” on the principle that attributes anything striking or bright in nature to satanic forces. Gray gives another name, Grim the Collier, that refers to a traditional character who gets the best of the devil in folk tales, putting our subject on the side of good rather than evil.

This would be an ordinary dandelion-like weed, except that the flowers are bright orange, making it one of our showiest wild flowers. It seldom or never [obviously this is not true] comes as far south as the city of Pittsburgh itself, but begins to be seen in the northern fringes of our area, and becomes quite common farther north in Pennsylvania.

This species is often placed in the genus Pilosella, but there seems to be much uncertainty. The imperfectly omniscient Wikipedia leads us on a merry chase: Hieracium aurantiacum redirects to Pilosella aurantiaca, but Pilosella redirects to Hieracium. [This is still true three years later.]

Gray describes the genus and the species:

Heads 12-many-flowered. Involucre more or less imbricated. Achenes short, oblong or columnar, striate, not beaked; pappus a single row of tawny and fragile capillary rough bristles. —Hispid or hirsute and often glandular perennials, with entire or toothed leaves, and single or panicled heads of mostly yellow flowers; summer and early autumn. (Name from hierax, a hawk.)

* Flowers orange-red.

H. aurantiacum L. (ORANGE H., DEVIL’S PAINT-BRUSH, GRIM THE COLLIER.) Long-hirsute; leaves oblanceolate, 6-15 cm. long, green on both sides; a stolons numerous, slender; scape 2-6 dm. high, usually 1-2-bracted; heads about 2 cm. broad. Fields, etc., e. Que. to Ont. and Pa., locally too abundant. June, July. (Nat. from Eu.)

Blue Vervain (Verbena hastata)

Verbena-hastata-2013-08-14-Schenley-Park-01The tiny flowers of this cheerful plant make a fine display—not too ostentatious, but elegant and striking. This one was growing in a field in Schenley Park, where it was blooming in the middle of August.

More pictures of this species are here, where you will also find quite a bit of lore taken from old books.

Gray describes the genus and the species:

VERBENA [Tourn.] L. VERVAIN. Calyx 5-toothed, one of the teeth often shorter than the others. Corolla tubular, often curved, salver-form; the border somewhat unequally 5-cleft. Stamens included, the upper pair occasionally without anthers. Style slender; stigma mostly 2-lobed. — Flowers sessile, in single or often panicled spikes, bracted, produced all summer. (The Latin name for any sacred herb; derivation obscure.) — The species present numerous spontaneous hybrids.

§ 1. Anthers not appendaged; flowers small, in slender spikes.

Spikes thicker or densely flowered; the fruits crowded, mostly overlapping one another; bracts inconspicuous, not exceeding the flowers; perennial.

V. hastàta L. (blue V.) Tall (0.5-2 m. high); leaves lanceolate or oblong-lanceolate, taper-pointed, cut-serrate, petioled, the lower often lobed and sometimes halberd-shaped at base; spikes linear, erect,corymbed or panicled; flowers violet-blue (rarely pink or white). —Damp grounds, etc.


Swamp Rose-Mallow (Hibiscus moscheutos)


These gorgeous flowers are the ancestors of many of our garden Hibiscus varieties. There are two main color variants: white with dark red eye (forma peckii  in older botanists) and the more common solid pink. They are not terribly common here, but locally abundant, as they were in this swamp in Cranberry, where they were blooming in late August. The USDA PLANTS database reports this species only in Allegheny and Fayette Counties in our area, but this colony was very near the line between Allegheny and Butler counties, and we are not entirely sure on which side of the border.

These pictures were taken with a cell phone while the photographer was standing knee-deep in poison ivy beside a busy four-lane highway. They are not ideal photographs, but, considering the circumstances, they are adequate. Such are the sacrifices we make to document the flora of southwestern Pennsylvania for you.

Hibiscus-moscheutos-2013-08-22-Cranberry-02Gray describes the genus and the species:

HIBÍSCUS L. Rose Mallow

Calyx involucellate at the base by a row of numerous bractlets, 5-cleft. Column of stamens long, bearing anthers for much of its length. Styles united, stigmas 5, capitate. Fruit a 5-celled loculicidal pod. Seeds several or many in each cell. — Herbs or shrubs, usually with large and showy flowers. (An old Greek and Latin name of unknown meaning.)

H. Moscheùtos L. (swamp R.) Tall perennial (1-2.6 m. high); the ■tern puberulent above; leaves ovate, pointed, toothed, the lower and sometimes the upper 3-Iobed, downy-whitened underneath, glabrous or slightly downy above: calyx and bracts densely stellate-puberulent; calyx in anthesis 2-3 cm. long, its lobes ovate or ovate-oblong; petals 6-12 cm. long, rose-color; capsule glabrous, subglobose, abruptly beaked. — River-banks and fresh or brackish marshes, near the coast, e. Mass., southw.; also lake-shores and swamps (especially near salt springs) westw. to Ont. and Mo. July-Sept.

Gray makes the crimson-eyed form a separate species, but it seems clear that in Cranberry, at least, it is the same species as the pink form:

Cut-Leaf Teasel (Dipsacus laciniatus)


Dipsacus-laciniatus-2013-08-21-Cranberry-01Very similar to the ordinary Teasel (Dipsacus fullonum), but with white flowers rather than pink ones.  In Gray’s time it was known in the North American wild only around Albany, but has since spread from New York to Pennsylvania and much of the Midwest. In Pittsburgh, it seems to be established especially along long-distance expressways, with large stands along Interstate 79 in Robinson Township and more along the Pennsylvania Turnpike; these grew in a debris-strewn vacant lot just off the Pennsylvania Turnpike in Cranberry. They may be thorny and destructive weeds, but they are favorites with bumblebees, as we see above.

Gray describes the genus and the species:

DÍPSACUS [Tourn.] L. TEASEL. Involucre many-leaved, longer than the chaffy leafy-tipped bracts among the densely capitate flowers; each flower with a 4-leaved calyx-like involucel investing the ovary and fruit (achene). Calyx-tube adherent to the ovary, the limb cup-shaped, without a pappus. Corolla nearly regular, 4-cleft. Stamens 4, inserted on the corolla. Style slender.—Stout and coarse biennials, hairy or prickly, with large ovoid-ellipsoid heads. (Name from dipsen, to thirst, probably because the united cup-shaped bases of the leaves in some species hold water. )

D. laciniatus L. Leaves pinnatifid or bipinnatifid, finely and rather conspicuously ciliate; leaves of the involucre lance-linear, spreading, usually shorter than the head. — Established at Albany, N. Y. (Peck). (Adv. from Eu.)

Rhododendron (Rhododendron maximum)


Big bushes with large, leathery evergreen leaves and ball-like clusters of white flowers, these ancestors of garden Rhododendrons are unmistakable. The only thing that resembles them at all is the Mountain Laurel, whose leaves and flowers are much smaller.

The flowers are white, often blushed with pink, especially when they are young. The upper petal is marked with greenish-yellow spots.

Rhododendron can grow in deep shade, although it seems to bloom more prolifically in the sun. These were growing in the woods along the Trillium Trail in Fox Chapel, where they were blooming in the middle of July.

Gray describes the genus and the species, which he places in the Eurhododendron or Rhododendron-proper section of the genus.

RHODODÉNDRON L. Calyx mostly small or minute. Stamens sometimes as few as the corolla-lobes, more commonly twice as many, usually declined; anther-cells opening by a round terminal pore. Capsule 5-celled, 5-valved, many-seeded. Seeds scale-like.— Shrubs or small trees, of diverse habit and character, with chiefly alternate entire leaves, and large and showy flowers in umbeled clusters from terminal buds. (Rhododendron, rose-tree; the ancient name.)

EURHODODÉNDRON DC. Leaves coriaceous and persistent; stamens (commonly 10) and style rarely exserted, somewhat declined, or sometimes equally spreading.

R. máximum L. (GREAT LAUREL.) Shrub or tree, 2-10 m. high; leaves 0.8-2 dm. long, very thick, elliptical-oblong, or lance-oblong, acute, narrowed toward the base, very smooth, with somewhat revolute margins; pedicels viscid, corolla bell-shaped, 3.5-5 cm. broad, pale rose-color or nearly white, greenish in the throat on the upper side, and spotted with yellow or reddish. — Damp deep woods, rare from N. S., Me., and Que. to Ont. and O., but very common through the Alleghenies from N. Y. to Ga. June, July.

Indian Pipes (Monotropa uniflora)

Monotropa-uniflora-2013-07-29-Frick-Park-01As they age (which happens very quickly), the dangling bells of these peculiar plants turn more and more upward; eventually, when they go to seed, they will be completely vertical. These plants were found deep in the woods in Frick Park in late July. A picture of a different plant in an earlier stage is here, and we repeat our remarks:

Indian Pipes are strange little plants that have no chlorophyll. They get their food by theft: they steal it from little fungi in a process called myco-heterotrophy. It was formerly believed that they were saprophytes, gaining their nutrition by breaking down decaying matter, but apparently they find it more convenient to employ fungi to do the hard work. Since they have no chlorophyll, they have no particular need for light; and they are often found deep in the woods.

Gray describes the genus and the species,which he puts in the section Eumonotropa or Monotropa proper:

MONÓTROPA L. INDIAN PIPE, PINESAP. Calyx of 2-5 lanceolate bract-like scales, deciduous. Corolla of erect spatulate or wedge-shaped scale-like petals, which are gibbous or saccate at the base, and tardily deciduous. Stamens 8 or 10; filaments awl-shaped; anthers becoming 1-celled. Style columnar; stigma disk-like, 4-5-rayed. Capsule ovoid, 8-10-grooved, 4-5-celled, loculicidal; the very thick placentae covered with innumerable minute seeds, which have a very loose coat. — Low and fleshy herbs, tawny, reddish, or white, parasitic on roots, or growing on decomposing vegetable matter; the clustered stems springing from a ball of matted fibrous rootlets, furnished with scales or bracts in place of leaves, 1-several-flowered; the summit at first nodding, in fruit erect. (Name composed of monos, one, and tropos, turn, the summit of the stem being turned to one side.)

§ 1. EUMONÓTROPA Gray. Plant inodorous, 1-flowered; calyx of 2-4 irregular scales or bracts; anthers transverse, opening equally by 2 chinks; style short and thick.

M. uniflora L. (Indian Pipe, Corpse Plant.) Smooth, waxy-white, flesh-color, or rarely deep red, turning blackish in drying. 0.6-3 dm. high; stigma naked. — Dark and rich woods, nearly throughout the continent. June-Aug. (Мех., Asia.)

Black Cohosh (Actaea racemosa)

Actaea-racemosa-2013-07-04-Mount-Lebanon-03Also known as Fairy Candles for the way it lights up the deep shade of the woods, or as Black Snakeroot, or Bugbane, and more commonly placed in the genus Cimicifuga until recently. It can tolerate a very shady location, and often grows in thick woods. This plant was one of a small colony growing on a thickly wooded hillside in Mount Lebanon, where it was blooming in early July. Another picture of the same plant, but in a different year, is here.

Flowers. Tiny, white, in forked racemes 3 or more feet (a meter) tall, occasionally up to 9 feet (3 meters); the stamens are the most visible part.

Leaves. Large, smooth, in whorls of 3, each doubly compound leaf made of three leaflets which themselves are subdivided in three or five leaflets; the leaflets irregularly and jaggedly toothed, the terminal leaflet usually 3-lobed.

Stems. Smooth, with enlarged purplish joints where the leaves are joined; some whitish bloom on the lower part.

Gray describes the genus Cimicifuga and the species, which he places in the Macrotrys subgenus:

CIMICÍFUGA L. BUGBANE. Sepals 4 or 5, failing off soon after the flower expands. Petals, or rather transformed stamens, 1-8, small, on claws, 2-horned at the apex. Stamens as in Actaea. Pistils 1-8, forming dry dehiscent pods in fruit. — Perennials, with 2-3-ternately divided leaves, the leaflets cut-serrate, and white flowers in elongated wand-like racemes. (Name from cimex, a bug, and fugere, to drive away.)

MACRÒTRYS (Raf.) T. & G. (as Macrotys). Pistil solitary or sometimes 2-3, sessile; seeds smooth, flattened and packed horizontally in the pod in two rows, as in Actaea; stigma broad and flat.

C. racemòsa (L.) Nutt. (BLACK SNAKEROOT, BLACK COHOSH.) Stem 1-2.0 rn. high, from a thick knotted rootstock; leaves 2-3-ternately and then often quinately compound; leaflets subcuneate to subcordate at the base; racemes in fruit becoming 3-9 dm. long; pods ovoid. — Rich woods, s. N. E. to Wise, and southw.; cultivated and escaped eastw. July.

[Because modern botanists have moved this species over to the genus Actaea, we give Gray's description of that genus as well:

ACTAÈA L. BANEBERRY, COHOSH. Sepals 4 or 6, falling off when the flower expands. Petals 4-10, small, flat, spatulate, on slender claws. Stamens numerous, with slender white filaments. Pistil single; stigma sessile, depressed, 2-lobed. Seeds smooth, flattened, and packed horizontally in 2 rows. — Perennials, with ample 2-3-ternately compound leaves, the ovate leaflets sharply cleft and toothed, and a short and thick terminal raceme of white flowers. (From aktea, actaea, ancient names of the Elder, transferred by Linnaeus.)]

Bee-Balm (Monarda didyma)


Monarda-didyma-2013-07-14-North-Park-01Also called Bergamot, Oswego-tea, and several other names.

Monarda is a fascinating example of parallel evolution: it makes a display by clustering small ray-like flowers together in one head so closely that the head is often taken for a single flower. In other  words, it adopts the method of the Compositae. This particular species is bright red, which is a very attractive color to hummingbirds. It is otherwise very similar to Wild Bergamot (M. fistulosa), which is rather more common around here.

This is a native perennial, but much used as an ornamental planting, so that it is difficult to distinguish truly wild populations from garden escapes. These plants are probably truly wild; both grew in North Park, where they were blooming in the middle of July. The species is very adaptable to different light conditions: one of these plants was growing in full sun,and the other deep in the woods where a fallen tree had opened up the sky just a bit.

Gray describes the genus and the species:

MONÁRDA L. HORSE MINT. Calyx 15-nerved, usually hairy in the throat. Corolla elongated, with a slightly expanded throat; lips linear or oblong, somewhat equal, the upper erect, entire or slightly notched, the lower spreading, 3-lobed at the apex, its lateral lobes ovate and obtuse, the middle one narrower and slightly notched. Stamens elongated, ascending, inserted in the throat of the corolla. — Odorous erect herbs, with entire or toothed leaves, and large attractive flowers in a few verticels closely surrounded by bracts. (Dedicated to Nicolás Monardes, author of many tracts upon medicinal and other useful plants, especially those of the New World, in the latter half of the 16th century.)

Stamens and style exserted beyond the linear straight acute upper lip of the corolla; heads solitary and terminal or sometimes 2 or 3; leaves acutely more or less serrate; perennials.

Leaves petioled; calyx-teeth scarcely longer than the width of the tube.

Glabrous or villous.

Calyx smooth or smoothish in the throat.

M. didyma L. (Oswego Tea, Bee Balm.) Stem somewhat hairy, 2 m. or less high, acutely 4-angled; leaves ovate-lanceolate, acuminate, the floral ones and the large outer bracts tinged with red; calyx smoothlsh, nearly naked in the throat; corolla smooth or minutely pubescent, 4-5 cm. long, bright red, showy. — Moist woods, by streams, w. Que., Out., and south w. July, Aug.

Pittsburgh Pest (Galinsoga parviflora)


Obviously this is not known as Pittsburgh Pest everywhere in its nearly global range, but the name seems to be well established here. It has many other names in English, including the delightful folk etymology “Gallant Soldiers.” It comes originally from South America, where it is a popular ingredient in Colombian cuisine.

The flowers are like tiny five-rayed daisies; the plant is low and hairy,and can grow from any crack in the pavement. This one grew at the edge of a sidewalk in Greenfield, where it was blooming in the middle of July. It is very much an urban weed, ubiquitous in the city of Pittsburgh, but much rarer in the near suburbs, and unknown in all the other counties of the metropolitan area but one (Washington County).

Gray describes the genus and the species:

GALINSÒGA R. & P. Heads several-flowered, radiate; rays 4-6, small, roundish, pistillate. Involucre of 4-5 ovate thin bracts. Receptacle conical, with narrow chaff. Pappus of small oblong cut-fringed chaffy scales, sometimes wanting. — Annual herbs, with opposite triple-nerved thin leaves, and small heads; disk yellow; rays white or reddish. (Named for Dr. Mariano Martinez de Galinsoga, a Spanish botanist.)

Rays white; pappus of disk-flowers about equaling the achenes.

G. parviflòra Cav. Pubescence subappressed; leaves ovate, crenate-serrate, petioled; pappus of the disk-flowers of spatulate obtusish scales.— Roadsides and waste places, from N. E. across the continent. (Adv. from Trop. Am.) Var. Híspida PC. Pubescence more copious, not appressed; pappus-scales of the disk-flowers attenuate and bristle-tipped. — Me. to Ont., Wise., and southw. (Nat. from Trop. Am.)

Indian Pipes (Monotropa uniflora)


Monotropa-uniflora-2013-07-15-Mount-Lebanon-03Indian Pipes are strange little plants that have no chlorophyll. They get their food by theft: they steal it from little fungi in a process called myco-heterotrophy. It was formerly believed that they were saprophytes, gaining their nutrition by breaking down decaying matter, but apparently they find it more convenient to employ fungi to do the hard work. Since they have no chlorophyll, they have no particular need for light; and they are often found deep in the woods. These, however, grew under a maple tree in a shady lawn in Mount Lebanon, where they were blooming in the middle of July.

Gray describes the genus and the species,which he puts in the section Eumonotropa or Monotropa proper:

MONÓTROPA L. INDIAN PIPE, PINESAP. Calyx of 2-5 lanceolate bract-like scales, deciduous. Corolla of erect spatulate or wedge-shaped scale-like petals, which are gibbous or saccate at the base, and tardily deciduous. Stamens 8 or 10; filaments awl-shaped; anthers becoming 1-celled. Style columnar; stigma disk-like, 4-5-rayed. Capsule ovoid, 8-10-grooved, 4-5-celled, loculicidal; the very thick placentae covered with innumerable minute seeds, which have a very loose coat. — Low and fleshy herbs, tawny, reddish, or white, parasitic on roots, or growing on decomposing vegetable matter; the clustered stems springing from a ball of matted fibrous rootlets, furnished with scales or bracts in place of leaves, 1-several-flowered; the summit at first nodding, in fruit erect. (Name composed of monos, one, and tropos, turn, the summit of the stem being turned to one side.)

§ 1. EUMONÓTROPA Gray. Plant inodorous, 1-flowered; calyx of 2-4 irregular scales or bracts; anthers transverse, opening equally by 2 chinks; style short and thick.

M. uniflora L. (Indian Pipe, Corpse Plant.) Smooth, waxy-white, flesh-color, or rarely deep red, turning blackish in drying. 0.6-3 dm. high; stigma naked. — Dark and rich woods, nearly throughout the continent. June-Aug. (Мех., Asia.)

Tall Meadow-Rue (Thalictrum polygamum)

Thalictrum-polygamum-2013-07-14-North-Park-01The clusters of airy flowers have no petals; it’s the white stamens that put on the show. The triple-compound leaves are very Columbine-like. As the common name implies, Tall Meadow-Rue can be quite tall—easily taller than a person. But it manages to look delicate and refined even at its tallest.

This plant likes a wet environment, and this one was growing beside a lake in North Park, where it was blooming in the middle of July.

Gray describes the genus and the species:

THALÍCTRUM [Tourn.] L. MEADOW RUE. Sepals 4-5, petal-like or greenish, usually caducous. Petals none. Achenes 4-15, grooved or ribbed, or else inflated. Stigma unilateral. Seed suspended. — Perennials, with alternate 2-3-ternately compound leaves, the divisions and the leaflets stalked; petioles dilated at base. Flowers in corymbs or panicles, often polygamous or dioecious. (A Greek name of an unknown plant, mentioned by Dioscorides.)

Flowers dioecious or polygamous.

Achenes sessile or subsessile, thin-walled, the ribs often connected by transverse reticulations; leaves 3-4-ternate.

Filaments club-shaped, ascending or spreading until after anthesis.

T. polygamum Muhl. (tall M.) Glabrous or pubescent but not glandular, 0.5-2.6 m. high; stem-leaves sessile; leaflets rather firm, roundish to oblong, commonly with mucronate lobes or tips, sometimes puberulent beneath; panicles very compound; flowers white (rarely purplish), the fertile ones with some stamens; anthers not drooping, small, oblong, blunt, the mostly white filaments decidedly thickened upwards; achenes glabrous. (T. Cornuti Man. ed. 5, not L.) — Wet meadows and along rivulets, Nfd. to O. and southw., common. July-Sept. Var. hebecarpum Fernald. Leaflets usually pubescent beneath; achenes pubescent. — Nfd. to s. Ont, and N. H.

Pickerelweed (Pontederia cordata)

Pontederia-cordata-2013-07-01-North-Park-01A common sight around the margins of ponds and lakes; this stand grew in North Park, where it was blooming at the beginning of July. The spikes of blue flowers and stiff arrowhead-shaped (or elongated-heart-shaped) leaves are distinctive: you will find nothing else that looks like this standing in shallow water.

Gray describes the genus and the species:

PONTEDÈRIA L. PICKEREL-WEED. Perianth funnel-form, 2-lipped; the 3 upper divisions united to form the 3-lobed upper lip; the 3 lower spreading, and their claws, which form the lower part of the curving tube, more or less separate or separable to the base; tube after flowering revolute-coiled. Stamens (3; the 3 anterior long-exserted; the 3 posterior (often sterile or imperfect) with very short filaments, unequally inserted lower down; anthers versatile, oval, blue. Ovary 3-celled; two of the cells empty, the other with a single suspended ovule. Utricle 1-celled.— Stout herbs, with thick creeping rootstocks, producing erect long-petioled leaves, and a 1-leaved stem, bearing a spike of violet-blue ephemeral flowers. Root-leaves with a sheathing stipule within the petiole. (Dedicated to Pontedera, Professor at Padua in the 18th century.)

P. cordata L. Leaves heart-shaped, blunt; spike dense, from a spathe-like bract; upper lobe of perianth marked with a pair of yellow spots (rarely all white); calyx-tube in fruit crested with 6-toothed ridges. — N. S. to Ont., Minn., and Tex. July-Sept. (Trop. Am.) Var. Angustifolia Torr. Leaves lanceolate or triangular-attenuate, roundish or truncate at base. — Same range.


Helleborine (Epipactis helleborine)


A spike of fascinating little orchid flowers, with broad pointed leaves alternate on the stem. The distinctive flowers have lips that look like little slippers filled with chocolate sauce. The color of the flowers is quite variable, according to botanical references; they may be yellowish, or green, or purple.  The species probably came from Europe, apparently as a medicinal herb, and by the middle 1800s had established itself on our continent.

The species is quite uncommon around here, though it seems there are a few places in North America where it can be an annoying weed. (UPDATE: Having written this, we discovered the very next day that one of those places is Schenley Farms, where Helleborine grows abundantly on otherwise neatly kept shady front banks.) This plant grew in the woods in Frick Park, where it was blooming in early July.

Gray calls the genus by an alternate name, Serapias:

SERÀPIAS L. Flowers in a loose or somewhat dense bracteose raceme. Sepals ovate-lanceolate, strongly keeled. Petals shorter, ovate, acute. Lip strongly saccate at base, the apical part broadly cordate, acute, with a raised scallus in the middle and two inconspicuous nipple-like protuberances on each side near the point of anion with the sac. Column broad at the top, the basal part narrower; anther sessile, behind the broad truncate stigma on a slender-jointed base; pollen farinaceous, becoming attached to the gland capping the small rounded beak of the stigma. — Stem leafy. (Named for the Egyptian deity Serapis.) Epipactis of auth., not Boehm.

S. helleborine L. Plants 25-60 cm. high; leaves clasping the stem, conspicuously nerved, broadly ovate to lanceolate, acute; perianth about 8 mm. long, green suffused with madder-purple; lip similarly colored, but darker within, the apical portion as if jointed with the sac, bituberculate at base. (Epipactis helleborine Crantz; E. latifolia All.; E. viridiflora Reichenb.) — Rare and local, Que. and Ont. to Mass., N. T., and Pa. —Probably introduced from Europe in early times on account of supposed medicinal value. July-Aug. (Eu.)


Catalpa (Catalpa bignonioides)



Also known in Pittsburgh as “Indian stogie” for its long, cigar-like seedpods. The combination of pyramids of white flowers and large, heart-shaped leaves marks the tree unmistakably as a Catalpa. But which one? There are, confusingly, two very similar species of Catalpa in our range, neither one of them strictly native. This one, the Southern Catalpa, is the only one recorded in Allegheny County; there is also a Northern Catalpa (C. speciosa) found in some of the suburbs.

This is very much an urban tree, planted originally as an ornamental, but now a very common weed tree in the city. It rapidly becomes less common as we get further out into the suburbs, and is completely unknown in Butler and Indiana Counties (where, however, the Northern Catalpa is sometimes seen). This tree was blooming in Frick Park in late June.

Gray describes the genus and the species:

CATALPA Scop. CATALPA. INDIAN BEAN. Calyx deeply 2-lipped. Corolla bell-shaped, swelling; the undulate 5-lobed spreading border irregular and 2-lipped. Fertile stamens 2, or sometimes 4; the 1 or 3 others sterile and rudimentary. Capsule very long and slender, nearly cylindrical, 2-celled, the partition at right angles to the valves. Seeds winged on each side, the wings cut into a fringe. —Trees, with ovate or cordate and mainly opposite leaves. (The aboriginal name.)

C. bignonioides Walt. A low much branched tree, with thin bark; corolla smaller (2.5-4 cm. long), thickly spotted, with oblique limb and entire lower lobe; capsule much thinner. (C. catalpa Karst.)—Naturalized from N. Y, southw.; indigenous on the Gulf coast.

Celandine Poppy (Stylophorum diphyllum)

Stylophorum-diphyllum-2013-05-08-Fox-Chapel-02Stylophoruum-diphyllum-2013-05-08-Fox-Chapel-01Like a larger version of the Celandine, this bright yellow poppy blooms at the same time, but is easily distinguished by its larger flowers with overlapping petals and bright orange stamens. This plant was blooming in early May along the Trillium Trail in Fox Chapel.

Gray describes the genus and the species:

STYLOPHORUM Nutt. CELANDINE POPPY. Sepals 2, hairy. Petals 4. Style distinct, columnar; stigma 2-4-lobed. Pods bristly, 2-4-valved to the base. Seeds conspicuously crested. — Perennial low herbs, with stems naked below and oppositely 2-leaved, or sometimes 1-3-leaved, and umbellately 1-few-flowered at the summit; the flower-buds and the pods nodding. Leaves pinnately parted or divided. Juice yellow. (From stylos, style, and pherein, to bear, one of the distinctive characters.)

S. diphyllum (Michx.) Nutt. Leaves pale beneath, smoothish, deeply pinnatifid into бог 7 oblong sinuate-lobed divisions, and the root-leaves often with a pair of small distinct leaflets; peduncles equaling the petioles; flower deep yellow (5 cm. broad); stigmas 3 or 4; pod ovoid. —Damp woods, w. Pa. to Wisc., ” Mo.,” and Tenn. May. —Foliage and flower resembling Celandine.

Star of Bethlehem (Ornithogalum umbellatum)


A European native that has made itself quite at home here, Star of Bethlehem can often be found in weedy patches of low grass. Until it blooms, its narrow leaves are hard to distinguish from the grass around them. The six-pointed white flowers are unmistakable, with six yellow-tipped stamens whose flattened “filaments” seem to form a miniature duplicate flower inside the larger one. This plant was blooming in late May beside a gas-station parking lot in Brookline.

Although most traditional references place the Star of Bethlehem in the lily family Liliaceae, modern botanists separate it into the asparagus family Asparagaceae.

Gray describes the genus and the species:

ORNITHÓGALUM [Tourn.] L. STAR OF BETHLEHEM. Perianth of 6 (white) spreading 3-7-nerved divisions. Filaments 6, flattened-awl-shaped. Style 3-sided; stigma 3-angled. Capsule roundish-angular, with few dark and roundish seeds in each cell, loculicidal. — Scape and linear channeled leaves from a coated bulb. Flowers corymbed, bracted; pedicels not jointed. (A whimsical name from ornis, a bird, and gala, milk.)

O. umbellàtum L. Scape 1-2.5 dm. high; flowers 5-8, on long and spreading pedicels; perianth-divisions green in the middle on the outside. — Escaped from gardens. (Introd. from Eu.)

Black Locust (Robinia pseudoacacia)

Robina-pseudoacacia-2013-05-18-Beechview-01This tree is ubiquitous in southwestern Pennsylvania, so it may come as some surprise to Pittsburghers that we live at the northern end of a native range that is actually very small, mostly in the Appalachians and foothills. The Black Locust has been much planted elsewhere, however, and may easily naturalize itself. It is in many ways an ideal urban tree: it grows fast, tolerates city conditions with no complaints, and has showy clusters of white pea flowers after most of the other flowering trees have stopped blooming. It does, however, have one serious flaw. Mature specimens are brittle, and can easily drop large branches in storms, crushing cars or bringing down power lines. When your power goes out in a thunderstorm, there’s a very good chance you have a Black Locust to blame.

The dangling chains of white pea-shaped flowers are unique among our native trees. Leaves are pinnately compound, with smooth-edged elliptical leaflets. The leaves often turn yellow and begin to drop in August, long before any other trees are even thinking about autumn. Mature trees have rough and shaggy bark, and often show scars of broken branches.

Gray describes the genus and the species (which he spells “Pseudo-Acacia”):

ROBÍNIA L. LOCUST. Calyx short, 5-toothed, slightly 2-lipped. Standard large and rounded, turned back, scarcely longer than the wings and keel. Stamens diadelphous. Pod linear, flat, several-seeded, at length 2-valved. — Trees or shrubs, often with spines for stipules. Leaves odd-pinnate, the ovate or oblong leaflets stipellate. Flowers showy, in hanging axillary racemes. (Named for John Robin, herbalist to Henry IV. of France, and his son Vespasian Robin, who first cultivated the Locust-tree in Europe.)

R. Pseùdo-Acàcia L. (common L., False Acacia.) Branches glabrous or glabrate; racemes slender, loose; flowers white, fragrant; pod smooth.— Along the mts., Pa. to Ga., and in the Ozark Mts. of Mo., Ark., and Okla.; commonly cultivated as an ornamental tree, and for its valuable timber, and naturalized in many places. May, June.

Yellow Archangel (Lamium galeobdolon)

Lamium-galeobdolon-2013-05-08-Fox-Chapel-01A European plant often cultivated here as a ground cover, but increasingly escaping into the wild. This plant was growing deep in the woods in Fox Chapel, on a hillside overlooking the Squaw Run, far from any cultivated planting. It is also commonly placed in the genus Lamiastrum, or “False Lamium.” So it is classified in the USDA PLANTS database, which records it as found in the wild in Pennsylvania. This particular plant, which shows the variegated leaves often found in cultivated varieties, was blooming in early May.

Gray describes the genus Lamium thus:

LAMIUM L. DEAD NETTLE. Calyx tubular-bell-shaped, about 5-nerved, with 5 nearly equal awl-pointed teeth. Corolla dilated at the throat; upper lip ovate or oblong, arched, narrowed at the base; the middle lobe of the spreading lower lip broad, notched at the apex, contracted as if stalked at the base; the lateral ones small, at the margin of the throat. Decumbent herbs, the lowest leaves small and long-petioled, the middle heart-shaped and doubly toothed, the floral subtending the whorled flower-cluster. (Name from lamos, throat, in allusion to the ringent corolla.)

This species is not described in the standard American botanical references, so we borrow a very thorough description from English Botany by James Sowerby.


Galeobdolon luteum, Ends. Sm. Engl. Bot. ed. i. No. 787. Koch, Syn. Fl. Germ. et Helv. ed. ii. p. 650. Galeopsis Galeobdolon, Linn. Sp. Pl. p. 810.

Perennial. Rootstock tufted or very shortly creeping. Barren shoots very long, trailing or arching, at length rooting. Flowering stems not rooting at the base, erect or ascending. Leaves stalked, ovate or deltoid-ovate, subcordate, slightly acuminate, acute, doubly or irregularly crenate-serrate. Verticillasters remote from each other. Lower bracts similar to the leaves, but narrower, and with shorter stalks; upper ones generally lanceolate, with a wedge-shaped base, more rarely similar to the lower ones. Calyx puberulent or sparingly bristly-hairy; teeth deltoid, abruptly acuminated into triangular points, sparingly ciliated or glabrous, and subspinous at the apex, spreading, not half the length of the tube; tube slightly curved and oblique at the mouth. Corolla tube rather longer than the calyx, with a conspicuous very oblique ring of hairs within, slightly curved upwards, without a projecting sac near the base on the lower side, suddenly enlarged towards the apex; upper hp greatly vaulted, obtuse, sparingly hairy; lower lip with the lateral lobes ovate-acuminate, the middle lobe a little larger, oblong, acuminated into a lanceolate point.

In woods and on hedge-banks, particularly on chalk and limestone formations. Local, but not uncommon in the south of England; rare in the north, where it extends north to Lancashire and Yorkshire. It has occurred in Scotland, but is scarcely deserving to be considered even as a naturalised plant. Rare, and very local in Ireland, where it is nearly confined to the east of the island.

England, [Scotland,] Ireland. Perennial. Spring, early Summer.

Rootstock many-headed, emitting numerous wiry radical fibres and producing flowering and barren stems, the latter in autumn attaining the length of 1 or 2 feet, and growing much in the same way as those of Vinca major. Flowering stems 9 inches to 2 feet high, more or less flexuous towards the base. Lamina of the leaves 1 to 2½ inches long. Verticillasters 6 to 10 flowered. Bracts 1½ to 3 inches long, the upper ones sometimes very narrow. Calyx yellowish-green. Corolla ¾ to 1 inch long, yellow, the lower lip bright yellow, with reddish-brown s pots and streaks; upper lip considerably more than half the length of the corolla; tube very short. Anthers destitute of the hairs which occur in all the other British species. Nucules generally abortive: at least I have never been able to find them mature. Plant light green, more or less thickly pubescent with rather stiff hairs, those on the stem deflexed.

The British plant has the upper bracts usually narrow, and is the Galeobdolon montanum of Reichenbach. Occasionally, however, I have seen the bracts all broad and similar to the leaves (G. luteum, Reich.), but the two forms certainly do not deserve to be called even varieties.

Yellow Archangel.
French, Lamier jaune. German, Goldnessel.

Solomon’s Seal (Polygonatum biflorum)


Little green bells dangle from arching stalks, almost invisible unless you look for them. The name “Solomon’s Seal” comes from the six-pointed scar left on the root by the withered stem; the species name “biflorum” refers to the plant’s habit of growing flowers in pairs. This plant was growing along the Trillium Trail in Fox Chapel,where it was blooming in early May.

Until flower buds appear, this plant and False Solomon’s Seal (Maianthemum racemosum) are hard to tell apart. Both have traditionally been placed in the lily family Liliaceae, but modern botanists have separated the Asparagus family Asparagaceae, taking the Solomon’s Seals with it.

Gray describes the genus and the species:

POLYGÓNATUM [Tourn.] Hill. SOLOMON’S SEAL. Perianth cylindrical, 6-lobed at the summit; the 6 stamens inserted on or above the middle of the tube, included; anthers introrse. Ovary 3-celled, with 2-в ovules in each cell; style slender, deciduous by a joint; stigma obtuse or capitate, obscurely 3-lobed. Berry globular, black or blue; the cells 1-2-seeded. — Perennial herbs, with simple stems from creeping knotted rootetocks, naked below, above bearing nearly sessile or half-clasping nerved leaves, and axillary nodding greenish flowers; pedicels jointed near the flower. (Name from poly-, many, and gony, knee, alluding to the numerous joints of the rootstock.)

P. biflòrum (Walt) Ell. (SMALL S.) Glabrous, except the ovate-oblong or lance-oblong nearly sessile leaves, which are commonly minutely pubescent as well as pale or glaucous underneath; stem slender (3-9 dm. high); peduncles 1-3- but mostly 2-flowered; perianth 10-12 mm. long; filaments papillose-roughened, inserted toward the summit of the perianth. (? P. boreale Greene; P. cuneatum Greene; Salomonta biflora Farwell.) — Wooded hillsides, N. B. to Fla., w. to Ont., e. Kan., and Tex.


Celandine (Chelidonium majus)


Not related to the Lesser Celandine, this greater Celandine is a member of the poppy family that likes to grow at the edge of the woods. These plants were growing by one of the tufa bridges in Schenley Park, where they were blooming in the middle of May.

Gray describes the genus and the species:

CHELIDONIUM [Tourn.] L. CELANDINE. Sepals 2. Petals 4. Stamens 16-24. Style almost none; stigma 2-lobed. Pod linear-cylindric, smooth, 2-valved, the valves opening from the bottom upward. Seeds crested. —Biennial herb with brittle stems, saffron-colored acrid juice, pinnately divided or 2-pinnatifid and toothed or cut leaves, and small yellow flowers in a pedunculate umbel; buds nodding. (Ancient Greek name, from chelidon, the swallow, because its flowers appear with the swallows.)

С majus L.— Rich damp soil about towns, centr. Me. to Ont., and southw., common from s. Me. to Pa. May-Aug. (Nat. 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.

Early Meadow Rue (Thalictrum dioicum)


Thalictrum-dioicum-2013-05-01-Fox-Chapel-02Long stamens dangle and wave in the breeze, identifying this this as a male plant. As the species name implies, this species has dioecious flowers (from Greek meaning “two houses”): that is, it bears male and female flowers on separate plants. The female flowers are little upright greenish clusters, but the male flowers are more common and more charming. In spite of the common name, Early Meadow Rue seems to prefer woods to meadows; this one was growing on a rocky hillside in the Squaw Run valley in Fox Chapel, where it was blooming at the beginning of May.

Gray describes the genus and the species:

THALÍCTRUM [Tourn.] L. MEADOW RUE. Sepals 4-5, petal-like or greenish, usually caducous. Petals none. Achenes 4-15, grooved or ribbed, or else inflated. Stigma unilateral. Seed suspended. — Perennials, with alternate 2-3-ternately compound leaves, the divisions and the leaflets stalked; petioles dilated at base. Flowers in corymbs or panicles, often polygamous or dioecious. (A Greek name of an unknown plant, mentioned by Dioscorides.)

Flowers dioecious or polygamous.

Achenes sessile or subsessile, thin-walled, the ribs often connected by transverse reticulations; leaves 3-4-ternate.

Filaments capillary, soon drooping; petioles of the stem-leaves well developed; vernal.

T. dioicum L. (EARLY M.) Smooth and pale or glaucous, 3-6 dm. high; leaves (2-3) all with general petioles; leaflets thin, light green, drooping, suborbicular, 3-7-lobed; flowers dioecious; sepals purplish or greenish white. — Rocky woods, etc., centr. Me., westw. and southw., common. Apr., May.


Ferdinand Schuyler Mathews gives us this description in his Field Book of American Wild Flowers:

“A beautiful but not showy, slender meadow rue with the staminate and pistillate flowers on separate plants. The bluish olive green leaves lustreless, compound, and thinly spreading; the drooping staminate flowers with generally four small green sepals, and long stamens tipped with terracotta, and finally madder purple. The pistillate flowers inconspicuously pale green. An airy and graceful species, common in thin woodlands. 1-2 feet high. Me., south to Ala., and west to Mo., S. Dak., and Kan.


Ellen Miller and Margaret Christine Whiting give us this fuller description in Wild Flowers of the North-Eastern States (1895):

“Found in rocky woods and hillsides during April and May.

“The branching leafy stalk grows from 1 to 2 feet high; smooth, round, and fine of fibre though strong; in color, green.

“The leaf is 3 or 4 times divided, terminating in groups of 3 leaflets on short slender stems; the leaflets are small, rounding, slightly heart-shaped at the base, and their margins are notched in rounded scallops; the texture is exceptionally fine and thin, the surface smooth; the color, a fine cool green.

“The flower is small and composed of 3 or 4 or 5 little, petal-like, pale green calyx-parts. Different plants bear the pistils and stamens; the flowers of the former are inconspicuous and sparse in comparison with those of the stamen-bearing plant: from these the many stamens, pale green faintly touched with tawny at the tips, droop on slender threads like little tassels. The flowers grow in loose clusters, on branching stems that spring from the leaf-joints.

“The Early Meadow Rue is unobtrusive in color and form, but most graceful in gesture, and fine in the texture and finish of all its parts; the leafage has a fern-like delicacy, and the flower tassels of the stamen-bearing plant are airily poised.”


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