No. 26. Convolvulus panduratus.
English Name—MECHAMECK BINDWEED.
French Name—Liseron mechamec.
German Name—Geigenblattrige winde.
Officinal Names—Convolv. pandurati seu Pseudo-mechoacana, radix.
Vulgar Names—Wild Potatoe, Wild Rhubarb, Mechameck, Wild Jalap, Man in the ground, Mecoacan, Potatoe Vine, Kussander, Kassader, &c.
Authorities—Linnaeus, Schoepf, Coxe, Disp. Bigelow Seq. B. Barton, Nuttal, W. Bart. V. M M. fig. 23.
Genus CONVOLVULUS—Calix five parted, segments unequal imbricated. Corolla bell or funnel shaped, limbus equal, nearly entire, with five folds and teeth. Five unequal stamina on the corolla. One pistil surrounded by a glandular disk, one style, stigma bifid or bilobe. Capsule bilocular, few seeded.
Species C. PANDURATUS—Root tuberose; stem twining; leaves cordate, acute, entire or pandurate; peduncles multiflore, calix mutic, corolla funnelshaped.
Description—Root perennial, very large, cylindric or fusiform, from two to four feet long, as thick as the arm, yellowish outside, whitish and milky inside, with many fissures, often branched below and attenuated above.—Stem procumbent or climbing, round, purplish, from three to twelve feet long, sometimes branched—Leaves cordate at the base, broad, alternate, petiolate, margin entire or undulate, or lobed on the sides like a fiddle, very sharp, but hardly acuminate, smooth, deep green above, pale green below.
Flowers in fascicles of two to six, on long peduncles, longer than the petioles, and axillary, pedicels unequal. Calix with five unequal segments, ovate obtuse, concave, mutic, two smaller opposite outside—Corolla large, funnel shaped, about two or three inches long, and as broad above, base tubulose, color white or incarnate or purplish. Stamina white, filaments filiform, unequal, inclosed, anthers oblong. Style white, filiform, stigma bipartite, segments linear. Capsule oblong, with two cells and four seeds.
History—A great botanical confusion had arisen in this genus, and the natural tribe of VOLVULIDES or Convolvulacea, of which it is the type. The genera of this family had not been well fixed, and Ipomea particularly was so little distinguished from Convolvulus that many species were considered as belonging to both! It is now ascertained (as I pointed out in a dissertation published in 1820) that the inequality of the stamina is the principal character of the family, and that Ipomea is distinguished, not by the variable corolla, but by the trilocular capsul and capitate or trilobe stigma. Both genera contain a multitude of species, many of which are medical, such as C. Scamonia, C. turpethum, C. jalapa, &c. which are all drastic or cathartic.
The true jalap of commerce has been ascribed to several plants, and a controversy exists on the subject. This plant is one of the false jalaps, the others are the Ipomea macrorhiza of Michaux, found from Georgia to Yucatan on the sandy shores, and several Bindweeds growing in South America. The true C. jalapa appears to grow on the Andes of South America and Mexico.
Our C. panduratus has also been mistaken for Scamony, Rhubarb and Mechoacan. The native name of Mechameck ought to be given to it as a distinctive appellation. It blossoms in summer, from June to August. It was named panduratus by Linnaeus, because the leaves are often lobed on the sides like a fiddle; but this does not always happen, and some plants have all the leaves cordate and entire.
The cathartic properties of this plant and of Ipomea macrorhiza have been denied by Bigelow, Baldwin, &c. and even the latter considered as edible; but it appears that all the species of these two genera, having milky roots, are more or less cathartic, particularly when fresh.
They both belong to PENTANDRIA monogynia of Linnaeus. Convolvulus, (like Evolvulus) derives from the twining habit of the genus.
Locality—Common all over the United States, from Canada and New England to Florida and Missouri, in poor and loose soils, sandy and slaty fields, gravelly hills and alluvions, open glades and thickets; but seldom in shady woods.
Qualities—The taste and smell of the root, approximate to Scamony and Jalap; but are less nauseous and acrid. This root may be known by its size, yellowish color, and crevisses. It is milky when fresh. The extract from it resembles Scamony and possesses the same properties.
Properties—Cathartic, diuretic and pectoral. It acts like jalap, rhubarb, briony and scamony at a larger dose, when given in substance; but the extract from the fresh root is more efficient, and is a mild cathartic at a small dose of ten or twelve grains. It is seldom used by physicians, but often by Indian doctors. It is a safe substitute for the more costly roots above mentioned, and as a root often weighs twenty pounds, it might be made an article of trade. As a diuretic it is useful in gravel, strangury, dropsy, &c. It enables to evacuate small calculous granulations, and may be taken in substance or decoction. As a pectoral it has been used for consumptive coughs and asthma; a syrup is made of it with Skunk cabbage, for that purpose.
Substitutes—Jalap—Rhubarb—Scamony—Briony—Erigeron Sp.—Pyrola umbellata—Asclepias tuberosa, &c.
Remarks—It is asserted that the Indians can handle Rattle-snakes with impunity, after wetting their hands with the milky juice of the root of this plant, or of Arum triphyllum.
Henry's figure is erroneous, having triangular leaves and bracteolate flowers.
The root must be collected at the end of summer; and if to be dried ought to be cut in slices.
Additions and corrections
26. CONVOLVULUS PANDURATUS—It is said that hogs eat the roots, and that Indians will handle snakes after washing their hands with the juice. The C. brasiliensis of South America is employed in decoction for dropsy.
Medical Flora, or Manual of the Medical Botany of the United States of North America, 1828, was written by C. S. Rafinesque.