Wild Flowers of Pittsburgh

Convolvulaceae

Dodder (Cuscuta gronovii)

A curious parasitic member of the Morning-Glory family. Dodder has no green coloring of its own because it has no chlorophyll; instead, a seedling must, within a few days of sprouting, attach itself to a suitable host plant, and begin to rob it of its sap.

There are many species of Dodder around the world, but this one is (as far as we know) the only one found in the Pittsburgh area, which makes it hard to misidentify. The stringy orange stems and the unearthly waxy flower clusters are unique. These vines were blooming along a tributary of Wexford Run in early September.

The genus Cuscuta usually makes its home in the family Convolvulaceae, the Morning-Glory Family; but it sometimes runs away from home and attempts to establish a household for itself as the family Cuscutaceae. Right now the botanical consensus seems to place it in Convolvulaceae.

Gray describes the genus and the species:

CÚSCUTA [Tourn.] L. DODDER. LOVE-VINE.

Calyx 5(rarely 4)-cleft, or of 5 sepals. Corolla globular-urn-ehaped, bellshaped, or short-tubular, the spreading border 5(rarely 4)-cleft, imbricate. Stamens with a scale-like often fringed appendage at base. Ovary 2-celled, 4-ovuled; styles distinct, or rarely united. Capsule mostly 4-seeded. Embryo spirally coiled in the rather fleshy albumen, sometimes with a few alternate scales (belonging to the plumule); germination occurring in the soil. — Leafless annual herbs, with thread-like yellowish or reddish stems, bearing a few minute scales in place of leaves; on rising from the ground becoming entirely parasitic on the bark of herbs and shrubs on which they twine, and to which they adhere by means of suckers developed on the surface in contact. Flowers small, cymose-clustered, mostly white, usually produced in summer and autumn. (Name supposed to be of Arabic derivation.)

Calyx gamosepalous; ovary and capsule pointed, the latter enveloped or capped by the marcescent corolla; flowers in loose panicled cymes.

Corolla-lobes obtuse, spreading.

C. gronòvii Willd. Stems coarse, often climbing high; corolla-lobes shorter than or equaling the deeply campanulate tube; scales copiously fringed; capsule globose, umbonate.— Wet shady places, N. S. to Man., and southw. — The commonest of our species. Very variable in size and compactness of clusters.


Morning Glory (Ipomoea purpurea)

An introduced ornamental that has become quite weedy, especially in the city of Pittsburgh, where it covers banks and winds through vacant lots with gay abandon. These vines grew on a fence in Beechview, where they were blooming at the beginning of September.

Flowers. Large and showy; trumpet-shaped, like an old phonograph horn; five-parted, with white center and contrasting darker markings radiating from the center. They come in several colors, from the deepest velvety purple to bright pink. They close by midday, or later if the weather is chilly or dark.

Leaves. Heart-shaped, or on vigorous and high-growing vines sometimes three-lobed, like a grape leaf; smooth above, lightly rough-hairy below; strongly veined.

Stem. Hairy; bright green; long and climbing; climbs by wrapping itself around any support, often bundling with other stems from the same plant, forming a dense mound; can climb to 9 feet (3 m) or so in one season.

Gray describes the genus and the species, which he places in the Euipomoea or Ipomoea-proper section of the genus:

IPOMOÈA L. MORNING GLORY. Calyx not bracteate at base, but the outer sepals commonly larger. Corolla salver-form or funnel-form to nearly campanulate; the limb entire or slightly lobed. Capsule globular, 4-6 (by abortion fewer)-seeded, 2-4-valved. (Nаmе, according to Linnaeus, from ips, a Bindweed, and homoios, like; but ips is a worm.)

§ 2. EUIPOMOÈA Gray. Corolla funnel-form or nearly campanulate, contorted in the bud; stamens and style not exserted

Lobes of stigma and cells 3, sepals long and narrow, attenuate upward, mostly hirsute below; corolla purple, blue, or white. (MORNING GLORY.)

I. purpurea (L.) Roth. (COMMON M.) Annual; stems retrorsely hairy; leaves heart-shaped, acuminate, entire; peduncles long, umbellately 3-5-flowered; calyx bristly-hairy below; corolla funnel-form, 4.5-7 cm. long, purple, varying to white. — Escaped in cultivated grounds. (Introd. from Trop. Am.)


Wild Potato Vine (Ipomoea pandurata)

A spectacular wild morning glory closely related to the sweet potato. It grows a similar starchy root that was an important food source for American Indians. Like many other members of the family Convolvulaceae, it really loves a chain-link fence, and here we see it growing on one in Beechview, where it was blooming in late July.

This species is somewhat unusual here compared to the far more common Bindweeds and Morning Glories. In Pennsylvania, it seems to grow south of a line drawn horizontally right across the center of the state, except that it has also been found near Erie.

Gray describes the genus and the species, which he places in the Euipomoea or Ipomoea-proper section of the genus:

IPOMOÈA L. MORNING GLORY. Calyx not bracteate at base, but the outer sepals commonly larger. Corolla salver-form or funnel-form to nearly campanulate; the limb entire or slightly lobed. Capsule globular, 4-6 (by abortion fewer)-seeded, 2-4-valved. (Nаmе, according to Linnaeus, from ips, a Bindweed, and homoios, like; but ips is a worm.)

§ 2. EUIPOMOÈA Gray. Corolla funnel-form or nearly campanulate, contorted in the bud; stamens and style not exserted.

• • Stigma 2-lobed or entire; cells 2, each 2-seeded; sepals broader, imbricated; leaves cordate, acuminate.

I. panduràta (L.) G. F. W. Mey. (WILD POTATO-VINE, MAN-OF-THE-EARTH.) Perennial, smooth or nearly so when old, trailing or sometimes twining; leaves occasionally contracted at the sides so as to be fiddle-shaped; peduncles longer than the petioles, 1-5-flowered; sepals smooth, ovate-oblong, very obtuse; corolla open-funnel-form, 4.5-8 cm. long, white, with purple in the tube. — Dry ground, Ct. to Ont., southw. and southwestw. June-Sept.— Stems long and stout, from a huge root, which often weighs 4-8 (-11) kg.


Hedge Bindweed (Calystegia sepium)

Also called Wild Morning Glory. Hedge Bindweeds do indeed love hedges, but they really come into their own on a chain-link fence. Most often the flowers are white, but sometimes we see a glorious bicolor like this one, which in size and color rivals the cultivated Morning Glory. This plant wove itself through a chain-link fence in Beechview, where it was blooming in late June.

Gray makes Calystegia a division of the genus Convolvulus. He describes the genus, division, and species:

CONVOLVULUS [Tourn.] L. BINDWEED
Corolla funnel-form to campanulate. Stamens included. Capsule globose, 2-celled, or imperfectly 4-celled by spurious partitions between the 2 seeds, or by abortion 1-celled, mostly 2-4-valved. Herbs or somewhat shrubby plants, twining, erect, or prostrate. (Name from convolvere, to entwine.)

CALYSTEGIA (R. Br.) Gray. Stigmas oval to oblong; calyx inclosed in
2 broad leafy bracts.

C. sepium L. (HEDGE B.) Glabrous or essentially so; stem high-twining or sometimes trailing extensively; leaves triangular-halberd-shaped, acute or pointed, the basal lobes obliquely truncate and often somewhat toothed or sinuate-lobed or merely rounded ; peduncles chiefly elongated, 4-angled; bracts rounded to sharp-acuminate at tip ; corolla white or rose-color, 3-5 cm. long. (Including var. americanus Sims.) Moist alluvial soil or along streams. June-Sept. (Eurasia.)


Morning Glory (Ipomoea purpurea)

Ipomoea-purpurea-05

These tropical garden escapes seem to love the Pittsburgh climate. They can cover whole hillsides or fences with twining vines that produce heart-shaped leaves, or sometimes three-lobed grape-like leaves when they really get large and vigorous. The flowers close by noon, giving us one of our best incentives for early rising.


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