This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Allspice, Pimenta officinalis. Was official in the eighth U. S. P.; but only the oil is now official (average dose, 3 minims). The action is the same as that of cloves, but it is more pungent in flavor. It is a useful condiment, improving digestion, somewhat as does capsicum, q. v. The volatile oil contains eugenol, as does oil of cloves.
The word "pimenta" is in lay use as referring to a variety of the Chile Pepper or Spanish Pepper, a slightly pungent species of Capsicum annum. This is known in French as "piment," in Portuguese as "pimento," and in Spanish as "pimiento." Some varieties are called "sweet pepper." The "hot pepper" is Capsicum fastigiatum, or the Mexican Chile and known in Europe as the African Pepper. The Spanish Pepper is largely official abroad, while we have entirely neglected it as a remedy, using only the capsicum. The various species of this plant are esteemed in tropical countries and are believed to act as an intestinal antiseptic. See "Capsicum" and "Piper."