The ripe fruit and bark of (1) Crataegus Oxyacantha, Linné, and (2) other species of Crataegus. (Nat. Ord. Rosaceae) 1. England and other parts of Europe and in Central and Northern Asia; 2. America.
Common Names: (1) English Hawthorn, May; (2) Haw, Red Haw, Hawthorn, Thorn.

Principal Constituents.—The fresh bark contains a water soluble, crystallizable, bitter body little soluble in alcohol. The flowers of the English hawthorn contain trimethylamine (N[CH3]3), a circulatory depressant.
Preparation.—Specific Medicine Crataegus. Dose, 5 to 60 drops.

Specific Indications.—Tentatively the indications for crataegus may be stated thus: Cardiac weakness, with valvular murmurs, sighing respiration, or other difficult breathing, especially when associated with nerve depression or neurasthenia; mitral regurgitation, with valvular insufficiency; cardiac pain; praecordial oppression; dyspnea; rapid and feeble heart action; marked anemia, associated with heart irregularity; cardiac hypertrophy; and heart-strain, due to over-exertion or accompanying nervous explosions.

Action and Therapy.—The bark, fruit and leaves of several species of the genus Crataegus have in the past been used as astringents and tonics. Though a well-known wild shrub of thickets and commonly cultivated hedge and ornamental plant, the English hawthorn seems to have largely escaped the exact investigators of medicinal plants until a quite recent date. In fact, crataegus is one of the most recently introduced medicinal agents of plant origin. Furthermore, it is distinctive in occupying almost wholly a position in cardiac therapy, though recognized to some extent as a general tonic. Investigators are divided as to its activity, some claiming it only as a functional remedy, while others go so far as to claim it curative of many heart irregularities, even in the presence of an actual organic disease of that organ. Among the conditions in which crataegus is accredited with good work are angina pectoris, endocarditis, myocarditis, and pericarditis, valvular incompetency with or without enlargement of the rings, rheumatism of the heart, dropsy depending on heart disorders, neuralgia of the heart, tachycardia, and in atheromatous conditions of the vessels. The exact indications are as yet none too well determined, enthusiastic admirers of the drug having unwittingly overestimated its power. There is no doubt, however, of its value in many of the conditions mentioned, especially the functional types; and there can be no question as to its value as a tonic to the heart-muscle. It is not poisonous, has no cumulative effect, and apparently from reports of a large number now using it, may be useful to control many of the symptomatic results depending upon a badly functionating or tired heart. Crataegus has been suggested to rest that organ and thereby guard against arteriosclerosis. It is a new remedy still on trial; and as yet with no rational explanation of its reputed powers. The smaller doses are suggested as more likely to succeed than full doses.

The Eclectic Materia Medica, Pharmacology and Therapeutics, 1922, was written by Harvey Wickes Felter, M.D.