Exogonium Jalapa, (Nuttall et Coxe) Baillon. The dried tuberous root, yielding not less than 7 p.c. of the total resins.

Habitat. E. Mexico, in damp, rich, shady woods; cultivated in India.

Syn. True Jalap, Vera Crux Jalap, Radix Jalapae; Fr. Jalap -- tubereux -- officinal; Ger. Tubera Jalapae, Jalapenwursel, Jalapenknollen, Jalape.

Ex-o-go'ni-um.. L. fr. Gr...., outside, + ..., offspring -- i.e., parts of generation (stamens, pistil) exserted -- extended above corolla.

Jal'a-pa. L. named after Jalapa or Xalapa, a city in Mexico, whence imported. Jal'ap. Formerly jal'op, English abbreviation from Jalapa.


Perennial twining herb; stems numerous, slender, twisted, furrowed, smooth, purplish, 3.6-6 M. (12-20 degrees) long, twining around neighboring objects; leaves exstipulate, 12-12.5 Cm. (4-5') long, cordate, entire, smooth, pointed, under side paler, prominently veined, on long petioles; flowers (Sept.-Nov., purple, salver-shaped, tube 5 Cm. (2') long, limb 5-7.5 Cm. (2-3') wide, in 3-flowered cymes, stamens exserted (exogonium). ROOT, fusiform, irregularly ovoid, pyriform, 4-15 Cm. (1 3/5-6') long, 1-10 Cm. (2/5-4') thick, often incised or cut into pieces; dark brown, longitudinally wrinkled or furrowed, numerous lenticels; hard, compact; not fibrous, internally grayish-brown, with distinct brown cambium line; odor slight, distinctive, smoky; taste somewhat sweet, acrid,


light brown -- numerous starch grains, .003-.035 Mm. (1/8325-1/725') broad, concentric or excentric lamellae, calcium oxalate rosette aggregates, tracheae, simple pores, secretory cells with yellowish-brown resinous contents. Solvents: diluted alcohol extracts virtues completely; water or alcohol alone only partially, each taking out a portion of purgative property, the alcoholic solution being more griping than the aqueous. Dose, gr. 5-20 (.3-1.3 Gm.).


False Jalap roots (Ipomaea simulans, I. Orizabensis), and roots of allied species; immature jalap roots, collected at improper times and containing very little resin; jalap roots deprived of resin by soaking in alcohol, becoming sticky to the touch, darker internally and thereby easily recognized; roots of other species of Exogonium and Ipomaea genera; mealy jalap, resembling the true root, but with mealy fracture and very few resin cells.


Plant resembles our Morning-glory, demands rich forest-loam and a climate suitable to Cinchona; grows on the eastern slope of the Mexican Andes, 1,500-2,400 M. (5,000-8,000 degrees) elevation, flourishes well in the Neilgherry, India, and is cultivated in Jamaica. It is trained upon trellises and various supports, and not disturbed until 3 years old and only thereafter every third year. Roots are dug in all seasons (hence varying appearance and strength), but chiefly in the spring, when young shoots appear, and in the autumn (best), after aerial stems have decayed, then washed, placed into nets and dried by holding over fire (there being no sunshine during the rainy season), which imparts a slight smoky odor and hydrates much of the quarters, or transversely that tends to make it less desirable; after drying it is put into bags (100-200 pounds; 45-90 Kg.) and shipped from Vera Cruz.


Resin 7-15-22 p.c., starch, gum 15 p.c., sugar 2 p.c., bassorin, coloring matter, ash 5-6.5 p.c.

Resin. -- Consists of: 1. Jalapin (probably identical with scammonin), 4-10 p.c., soft, waxy, soluble in ether, alkalies, reprecipitated by acids, and medicinally inert. 2. Jalapurgin, rhodeoretin, convolvulin, CHO, 90-96 p.c., a white, odorless glucoside, hard, insoluble in ether, soluble in alkalies, more of an irritant than jalapin and the chief active constituent; converted by alkalies into jalapurgic (convolvul(in)ic acid, which is soluble in water), CHO, by warming with diluted acids or emulsin into glucose, volatile methyl-ethyl-acetic acid, CHO, and convolvulic acid, and this latter by continued action into glucose and crystalline convolvulinolic acid, CHO; the name jalapin has unfortunately been assigned to both resins.


1. Pulvis Jalapae Compositus.  Compound Powder of Jalap.  (Syn., Pulv. Jalap. Co., Pulvis Purgans -- Catharticus or Jalapae tartaratus; Fr. Poudre de Jalap composee; Ger. Jalapenpulver mit Weinstein.)


35 p.c.  Triturate together jalap 35 Gm., potassium bitartrate 65; mix thoroughly, pass through No. 60 sieve.  It is light brown -- numerous sharp, angular, colorless, rectangular fragments, straight-edged, slowly soluble in water or chloral hydrate T.S., strongly polarizing light with strong display of colors (fragments of potassium bitartrate crystals); other elements of identification -- tissues of jalap.  Dose, gr. 15-60 (1-4 Gm.).

2. Resina Jalapae.  Resin of Jalap.  (Syn., Res. Jalap.; Br. Jalapae Resina; Fr. Resine de Jalap; Ger. Jalapenharz.)


Macerate, percolate 100 Gm. with alcohol until the percolate when dropped into water only produces slight turbidity (250 cc.), reclaim alcohol until percolate reduced to 25 Gm., and add this, constantly stirring, to water 300 cc., let precipitate subside, decant supernatant liquid, wash precipitate twice by decantation, each time with hot water 100 cc., drain, dry on water-bath.  It is in yellowish-brown masses, fragments, breaking with resinous, glassy fracture, translucent at edges, or yellowish-brown powder, slight, peculiar odor, somewhat acrid taste, permanent, soluble in alcohol, insoluble in carbon disulphide, benzene, fixed or volatile oils; alcoholic solution faittly acid.  Tests: 1. Shake occasionally for an hour in a stoppered flask 1 Gm. With 20 cc. of chloroform, wash flask and filter with 3 successive 5 cc. portions of chloroform, evaporate combined filtrates, dry residue -- should weigh .3 Gm.  2. Dissolve in ammonia water (5) -- solution not gelatinous on standing; acidify with hydrochloric acid -- only slight turbidity (abs. of rosin, guaiac, other resins).  Impurities: Rosin, guaiac, aloin, acid resins, other resins, water, soluble substances.  Dose, gr. 1-5 (.06-.3 Gm.).

Preps.: 1. Pilulae Hydrargyri Chloridi Mitis Compositae, 1/3 gr. (.02 Gm.).  2. Pilulae Catharticae Vegetabiles, N.F., 1/3 gr. (.02 Gm.).  3.  Fluidextractum Jalapae, N.F., 100 p.c. root (7 p.c. resin -- alcohol).  Dose, mij-10 (.3- .6 cc.).

4. Tinctura Jalapae, N.F., 20 p.c. root (1.4 p.c. resin -- 67 p.c. alcohol).  Dose, 3ss-1 (2-4  cc.).

5.Tinctura Jalapae Composita, N.F., 12.5 p.c. (root) + resin of ipomoea 3 p.c. (67 p.c.  alcohol).  Dose, 3ss-1 (2-4 cc.).

Unoff. Preps.: Abstract (alcohol), gr. 2-5 (.13-.3 Gm.).  Extract (alcohol, gr. 2-10 (.13-.6  Gm.).


Hydragogue cathartic, diuretic.  Has no effect until the duodenum is reached, where with the bile it forms a purgative compound that stimulates vascularity, peristalsis, and profuse secretion from intestinal glands, with no action on biliary flow; usually acts in 4 hours.  It is less irritating than gamboge, podophyllum, or scammony, but occasionally gripes, nauseates and vomits.  Often given to children for worms, as it has little taste and a safe action.  Excessive doses produce dangerous hypercatharsis.  Jalapurgin (convolvulin) in large doses is likewise an active irritant or poison.


Dropsy, constipation, in febrile and inflammatory affections, head troubles; was introduced into Europe early in the 17th century and is even now quite popular, being combined usually with calomel, cream of tartar, etc.