There are many names for this version of rum, citrus and sugar: “Planter’s Cocktail,” “Jamaican Rum Punch,” and most commonly, Planter’s Punch.
1/2 oz. fresh lime juice
1/2 oz sugar syrup*
2 oz. dark Jamaican rum
1/2 tsp. Grenadine
1/2 tsp. Falernum**
2 dashes Angostura bitters
1. Put ingredients into a blender with 3/4 cup of crushed ice. Blend at high speed for no more than five seconds.
2. Pour unstrained into a tall glass. If necessary, add ice to fill glass.
* Sugar syrup: Heat equal parts white sugar and water until sugar dissolves, then cool and store in a bottle. Sugar syrup is sold at liquor stores and gourmet markets as "rock candy syrup" or "simple syrup."
** Falernum: A ginger-lime syrup invented in the West Indies. Two brands available in the U.S. are Fee Brothers and John D. Taylor's Velvet.