Allspice is a single spice
The dried berries from this plant are redolent of a mix of spices. Whole or ground they seem to hold all the scents of our holiday baking favorites: cloves, cinnamon, and nutmeg. Its flavor matches its aroma; and this 'evidence,' along with the suggestive name, have duped people to believing it's a blend of spices for ages.
Allspice can be purchased whole and then ground at home as-needed to achieve maximum flavor. Be sure to account for this fresh-ground pungency by using less than the amount called for in your recipe.
Allspice tree plantations are called "walks." In midsummer these groves bloom with tiny white flowers that are intensely aromatic. A "pimento walk" according to mid 18th century botanists was a stroll through the grounds and avenues of allspice trees. Patrick Browne, one such botanist, declared "Nothing can be more delicious than the odour of these walks, when the trees are in bloom..."