Köhler’s jalap plate shows Ipomoea purga, a Mexican vine whose root was a powerful laxative. It’s plate 150 in Köhler’s Medizinal-Pflanzen, a German book of medicinal plants, and appears in volume 2, completed in 1890. It was printed in color as a chromolithograph.
What the plate shows
The plate shows the root tuber and a flowering stem at natural size, with the twining stem, heart-shaped leaves and purplish-red, fflowers with a long, narrow tube that opens into a flat face. Numbered details show the flower, the stamens, pollen, the calyx with the style and stigma, and the ovary, whole and cut lengthwise. Köhler credits the drawing to “Professor Schmidt in Berlin,” the botanical artist Carl Friedrich Schmidt.
The names
Köhler calls the plant Ipomoea purga Hayne. The last word credits the German botanist Friedrich Gottlob Hayne, who placed it in the genus Ipomoea, from the Greek for “like a woodworm,” after its twining stems. It belongs to the morning glory family. The word jalap comes from the Mexican town of Jalapa, today Xalapa, which supplied the drug, though Köhler notes the plant hardly grew there anymore.
Jalap as medicine
The tubers come from the humid mountain forests on Mexico’s eastern slopes and were dried over a fire, the bigger ones cut open first. Köhler names the dried tubers as the official medicine and lists them in 12 pharmacopoeias, including the German, British and American ones. Doctors gave jalap as a powder, pills or a tincture to purge the bowels. Its active part is a resin, which makes up 5 to 18% of the root.
The Ipomoea purga in our collection
The Ipomoea purga in our botanical art collection is a replica of this plate, finished by hand in our workshop.
