Tiger Tongue and Boat Money are associated with the Lan Chang Kingdom of Southeast Asia (now part of Laos and Thailand). The people of that region used flattened silver ingots that were tapered at the ends as their currency (known locally as "lat" or "small money"). These ingots were valued based on their weight.
One variety of lat is characterized by rows of raised bumps and, owing to its appearance, is known to collectors as "Tiger Tongue" Money. Another variety is smooth and has a distinct depression in the center, suggesting a boat, and hence it is referred to as "Boat Money" ("lad hoi" in the local dialect). Smaller versions of this, with ends that are less blunt, may be referred to as "Canoe Money." The first Tiger Tongues were probably produced in the 16th Century.