A parasitic fungus, Ustilago segetum, Bull (Ustilago Maydis [Maidis], Léveillé; Ustilago carbo, Tulasne), developed upon the fruit of Zea Mays, Linné.
COMMON NAMES: Corn-smut, Corn-ergot, Corn-brand.
Source, Formation, and History.—Ustilago is a parasitic fungus infesting the fruit of the common corn plant (Zea Mays, Linné). The "smutted" ear of corn appears blackened and shrivelled, the fungus, called Ustilago, from its burnt or charred appearance, exhibiting a smooth, gelatiniform membrane, containing a soot-like powder of minute, dark, spherical spores. Ustilago attacks many plants, as the ears of wheat, oats, and barley, and also various grasses, figs, violets, anemones, etc. The particular species infesting the ears of corn, is the Ustilago segetum, Bull. The condition produced is known popularly as the "smut of corn," or "brand of corn." The attack actually begins with the germination of the corn plant, for the hyphae of the fungus-spores enter the seedling when very young, and grow up within the plant, but does not manifest itself until the fruit begins to ripen, when the ears take on the characteristic sooty or smutty appearance, each bad grain being filled to bursting with the powdery spores. Only very young seedlings can be infested by this parasite, for, as the tissues of the plant become harder, the germinal tube, sent out from the sporidium, cannot effect an entrance into the tissues. The spores of Ustilago are largely conveyed to the plants through the distribution of barn-yard manures, in which the fungus appears to thrive and rapidly multiply. This parasitic disease was thought to be similar to that of ergot (see Ergota), but since 1860-66, the matter has been better studied, and the life-history of the fungus well worked out. (For an interesting and popular exposition of the fungous diseases of vegetation, see Diseases of Plants, by H. Marshall Ward.)
Description and Chemical Composition.—Ustilago is easily recognized as the large, black, or blackish excrescences (smut of corn) which form on the end of defective ears of corn, and give a dry, black powder, resembling lampblack. The masses are covered with a smooth, gelatin-like membrane, showing a slate-black color, due to the presence of the black spores within. The masses are quite large, sometimes 6 or more inches thick, globose or irregular, showing a lobular or obtusely-branched structure. It has a disagreeable taste, and a heavy, unpleasant odor. Moisture impairs its virtues, which, under the best of keeping, are not retained for more than 1 year.
Mr. John H. Hahn (Amer. Jour. Pharm., 1881, p. 496) obtained from cornsmut, by extraction with ether, 2.5 per cent of a dark-brown fixed oil of acid reaction, insoluble in alcohol, and having the odor of the drug. A variety of substances was isolated from corn-smut by C. J. Rademaker and J. L. Fischer (ibid., 1887, p. 445, from Medical Herald, 1887). The authors found fixed oil (6.5 per cent), resin (8 per cent), and wax (5.5 per cent), soluble in petroleum benzin; trimethylamine (1.5 per cent), crystallizable sclerotic or maisenic acid (2 per cent), wax (6.25 per cent), and resin (4.5 per cent), soluble in ether; sclerotic acid (0.5 per cent), and resin (3.5 per cent), soluble in alcohol; sugar (3.75 per cent), pectin (2.25 per cent), salts (4.5 per cent), and extractive (9.5 per cent), soluble in water, and a crystallizable alkaloid, ustilagine. It is white, bitter, soluble in ether, alcohol, and water, of alkaline reaction, forming crystallizable salts, soluble in water. The above sclerotic acid is probably not identical with that of Dragendorff (see Ergota).
Action, Medical Uses, and Dosage.—Ustilago appears to possess decided activity, its effects having been compared with those of ergot and nux vomica combined. Upon the lower animals it acts as a spinal excitant, producing tonic convulsions, and destroying life, either by tetanus or exhaustion. Full doses dilate the pupils. Ecbolic properties are conceded to it, and, by many, it is preferred to ergot for obstetrical uses, inasmuch as it appears to be less powerful, and to produce clonic instead of tonic uterine contractions. According to Ellingwood, with whom it is a favorite remedy, it produces perfectly regular intermittent and safe contractions. The following statements (since confirmed by other investigators) have been made concerning this agent: "Its action on the uterus is as powerful as the ergot of rye, and perhaps more" (Lindley). "Its use is attended with shedding of the hair, both of man and beast, and sometimes even of teeth. Mules fed on it lose their hoofs, and fowls lay eggs without any shells" (Rowlin). "It is doubtless by its abortifacient power that it causes the eggs of fowls to be extruded before there has been time for a shell to be formed. By what power does it cause the shedding of the hair of man and brute animals, and the casting off of the hoofs of mules long fed upon it?" (Prof. Tully). "In a cowhouse, where cows were fed on Indian corn infested with this parasite, 11 of their number aborted in 8 days. After their food was changed none of the others aborted" (Annal. Med. Netr. Belge, and Rép. de Ph.). The better to be convinced of the poisonous nature of this fungus, the author, after having dried and pulverized the drug, administered 6 drachms to two bitch dogs with young, which soon caused them to abort" (Dr. H. W. Burt, Amer. Homoeop. Obs., 1868, p. 305).
Ustilago was introduced into practice chiefly through the efforts of the Homoeopaths. Inasmuch as it acts promptly upon the gravid uterus, exciting contraction, it may be employed in labor, under the same circumstances, and observing the same precautions as named under ergot (see Ergota). It likewise controls postpartum hemorrhages and passive hemorrhages from the lungs and bowels. In minute doses, Prof Scudder (Spec. Med., p. 261) points out that it may be used "to relieve false pains, and unpleasant sensations in the pelvic region, during the latter months of pregnancy." Ustilago, in fractional doses (tincture of ustilago, gtt. x, to water, fl℥iv; dose, a teaspoonful, every 2, 3, or 4 hours), is of value in many disorders in which ergot or belladonna are useful, and sometimes acts better than either. The conditions are those of enfeebled spinal and sympathetic innervation, and sluggish capillary and venous circulation, with a tendency to passive hemorrhages. It serves a useful purpose in impaired cerebral circulation, with dizziness, unsteadiness of motion, or lack of command over the intellectual faculties, dull headache in top of head, disordered vision, etc. It is especially applicable in disorders of the spinal cord and cerebellum, resulting from masturbation and seminal pollutions. In the diseases peculiar to women, it has been successfully prescribed when the abdomen was lax and pendulous, the perineum full and relaxed, and the uterus weak, flabby, and increased in size. Thus it has proved useful in the following disorders, and in the reflex disturbances arising from them: Ovarian irritation, ovaritis, amenorrhoea, dysmenorrhoea, premature menstruation, and other menstrual derangements, metrorrhagia, from uterine subinvolution, turn of life, uterine catarrh, and agalactia. It also arrests prolonged lochial discharge, and gives a healthy tone to the uterine walls. The dose in these conditions should range from 5 to 30 drops of specific ustilago. Ustilago is said to affect the skin and its appendages, therefore it has been suggested in doses of 1 to 5 drops of specific ustilago, in alopecia, scalp diseases, with dryness, urticaria, with large, pale welts, and in early dental decay. Dose of ustilago, 1 to 20 grains; of specific ustilago, 1 to 60 drops; of the fluid extract, 1 to 60 drops; of the tincture, 1 to 60 drops.
Specific Indications and Uses.—Enfeebled spinal and sympathetic innervation; feeble capillary and venous circulation; impaired cerebral circulation, with dizziness and unsteadiness; sleeplessness from atony; uterine derangements, with excessive sanguineous or other discharges, lax or flabby uterine, vaginal, and perineal tissues, with uterine pain; pain in top of head; uterine inertia during labor; postpartum and passive hemorrhages.
King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.