The fruit of Oenanthe Phellandrium, Lamarck (Phellandrium aquaticum, Linné).
COMMON NAMES: Water fennel, Fine-leaved water hemlock, Water dropwort.
Botanical Source.—This plant is a biennial or perennial, umbelliferous herb, having a thick, spindle-shaped root, with many whorled fibers. The stem is hollow, furrowed, half immersed in the water, very bushy, with numerous spreading, leafy branches, and from 2 to 4 feet in height. The leaves are petioled, spreading, repeatedly pinnate, cut, with innumerable fine, expanded, dark-green, shining, acute segments. The umbels are opposite to the leaves, on shortish stalks, about 5-rayed, without any general bracts. Partial umbels are very dense, of numerous short rays, accompanied by many narrow, taper-pointed bracts. The flowers are white, numerous, all fertile, outer ones largest and most irregular; innermost more certainly prolific. Styles long, filiform, spreading, and capitate. Fruit ovate, rather compressed, purplish, smooth, oblong, crowned with the minute spreading calyx, and rather short, permanent, slightly spreading styles; the dorsal ridges distinct, but little elevated, the lateral ones much broader and thicker; all confluent below the calyx. The pedicels are shorter than the fruit (L.).
History and Description.—This plant is common to Europe, growing in ditches and wet places, and its leaves are reputed harmful to cattle, causing a species of palsy after eating it. It is poisonous, but not so dangerously so as the Oenanthe Crocata (Dead-tongue, or Hemlock dropwort; see Related Species), which is considered the most energetic poison of the narcotico-acrid Umbelliferae. By desiccation, they lose much of their poisonous properties. The O. Phellandrium is occasionally found in this country. The seeds are the parts used. They are about 1/12 inch long, of a yellowish -green color, elliptical, slightly curved, flat on one side and gibbous on the other, striated with 10 filiform ribs, and terminate in small, 5-toothed heads, the remains of the calyx and styles. They have a peculiar, strong odor, somewhat resembling angelica, and an acrid, spicy taste, owing to a volatile oil, which they contain in abundance.
Chemical Composition.—The seeds contain about 1.5 per cent of volatile oil and 19.5 per cent of fatty oil. Indications of an alkaloid have been variously observed (see Flückiger, Pharmacognosie, 3d ed., 1891, p. 953). It is probably the poisonous phellandrin of earlier chemists. The volatile oil has a penetrating, aromatic odor, a specific gravity of about 0.87, and contains 80 per cent of the terpene hydrocarbon phellandrene. It was discovered by Pesci (1883) in the seeds of this plant, from which it was named. It is present as dextro-phellandrene, which also occurs in other oils, while laevo-phellandrene is the chief constituent of certain Eucalyptus and other oils—e. g., Eucalyptus amygdalina. Phellandrene forms a characteristic nitrite, melting at 103° C. (217.4° F.). It is an unstable terpene, capable of polymerization into solid diphellandrene, or of being converted into the optically inactive isomer, dipentene.
Action, Medical Uses, and Dosage.—Water fennel is a mild narcotic stimulant, expectorant, alterative, and diuretic. In large doses, it produces dizziness, inebriation, and dull pains in the head. The seeds have been most successfully used in chronic affections of the air-passages, as laryngitis, asthma, hemoptysis, catarrh, etc.; also in periodical febrile diseases, dyspeptic affections, and in indolent ulcerations. They are given in powder, commencing with 4 or 5 grains, every 1 or 2 hours throughout the day, cautiously increasing the dose to 8 or 10 grains. Two parts each of powdered gum Arabic and sugar of milk may be mixed with 1 part of the powdered seeds, and divided into doses of 25 grains each, which may be repeated every 2 or 3 hours. Dr. Turnbull, of Liverpool, used the following tincture and extract: Take of well-bruised seeds of phellandrium, 16 ounces; alcohol, a sufficient quantity to displace by percolation 32 fluid ounces. The dose is from 1/2 to 1 fluid drachm. For the alcoholic extract, take of the seeds of phellandrium, bruised, 16 ounces; alcohol, 3 parts; displace by percolation, distill off 2 1/2 pints of alcohol, and evaporate the remainder to the consistence of an extract. The dose is from 3 to 5 grains, in pill. He recommended it highly in consumption and bronchitis, to relieve troublesome cough, render expectoration less and easier, and produce sleep at night. He believed the above preparations to contain all the beneficial properties of the seeds, and to act with more certainty and power.
Related Species.—Oenanthe Crocata, Linné (Oenanthe apiifolia), Nat. Ord.—Umbelliferae; Water hemlock, Water lovage, Water dropwort, Hemlock dropwort, Dead-tongue. Indigenous to England, France, Spain, and Sweden, thriving in swamps and moist situations. The root of this species is medicinal. This is an exceedingly poisonous plant. The active poisonous principle is a resinous matter, soluble in ether and alcohol, insoluble in water. An alkaloid could not be isolated (A. Vincent, Jour. Pharm. Chim., 1864, p. 140; also see microscopical investigation by H. W. Jones, Pharm. Jour. Trans., Vol. XVI, 1885, p. 357). The plant produces severe gastro-intestinal disturbances and convulsions. A number of cases of poisoning, some fatal, are recorded in Hale's New Remedies—Therapeutics. Small doses of the tincture have been advised in epilepsy by several writers in the Eclectic Medical Journal, Eclectic Medical Gleaner, and other journals. Doses of even 5 drops sometimes produce violent headache and other unpleasant symptoms, in which case the dose will have to be lessened.