Botanical Source.—This is an indigenous perennial plant, with long and soft whitish hairs, and a subsimple stem, from 1 to 2 feet in height. The leaves are sessile, nearly entire, lanceolate, acute at both ends, pilose beneath; floral ones not whitened. The flowers are white, in large, terminal, sessile heads. Calyx teeth ovate-lanceolate, acute, and with the lanceolate bracts canescently villous and awnless. Corolla pubescent; stamens exserted (G.—W.).
History.—This plant is found in low grounds, dry hills, and plains, from Ohio and Illinois extending southward, and flowering in July and August. The whole plant is used, and yields its virtues to boiling water. It has the taste and odor peculiar to the mint family.
Action, Medical Uses, and Dosage.—Pycnanthemum is diaphoretic, stimulant, antispasmodic, carminative, and tonic. A warm infusion is very useful in puerperal, remittent, and other forms of fever, coughs, colds, catarrhs, etc., and is of much benefit in spasmodic diseases, especially colic, cramp of the stomach, and spasms of infants. The cold infusion is a good tonic and stimulant during convalescence from exhausting diseases. Dose of the infusion, either warm or cold, from 1 to 4 fluid ounces, 3 or more times a day.
Related Species.—There are several species of this genus, which possess similar medicinal properties, as the Pycnanthemum clinopoiodes, Torrey and Gray; Narrow-leaf Virginian thyme, or Prairie hyssop, a pubescent plant with white flowers, sessile, lance-linear, entire, and punctate leaves, terminal and corymbed heads, and acuminate bracts. Also the P. aristatum, Michaux, or Wild basil, with lance-ovate, subserrate, pubescent, acuminate, and short petiolate leaves; hirsute, terminal, capitate, and subterminal verticils; bracts lance subulate, the calyx terminated by awns (G.—W.). P. incanum, also called Wild basil, Mountain mint, and sometimes Horsemint, is used like Monarda. P. linifolium, Pursh, is a smooth plant, also called Virginia thyme. This, as well as the P. lanceolatum, Pursh, which resembles it in its bitter, resinous taste, has been employed in dyspepsia and hydrophobia. Dr. Charles Mohr found in P. linifolium volatile oil, a caoutchouc-like resin, a bitter, greenish-yellow resin, soluble in 65 per cent alcohol, gum, some sugar, and tannin closely related to caffeotannic acid; no alkaloid (Proc. Amer. Pharm. Assoc., 1876, p. 515). Mr. Harold C. Barker, making a complete analysis of this species collected while in flower, confirmed the absence of alkaloids or glucosids (Amer. Jour. Pharm., 1894, p. 169). The same author found P. lanceolatum to contain at least 1.5 per cent of volatile oil, the odor of which resembles that of pennyroyal. Alkaloids, glucosids, and starch were absent, while tannin and small amounts of inulin and sugar were present (ibid., 1894, pp. 65 and 172).
King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.