LED typical and forward voltages
The important thing to realize is that CURRENT is what MATTERS to an LED. The voltage is given as a range because the voltage varies, depending on manufacturing tolerances, temperature, etc.

If you design well for LEDs, you feed them with a current source, and the voltage simply needs to be adequate for the number of LEDs you have in series on each current source. In figuring the voltage compliance your current source should have, look at the highest voltage quoted.

If you use resistors for current-limiting LEDs, use either the LOWEST value of forward voltage provided, or a bit less than that (safety margin) when choosing a resistor to set the current. This is sub-optimal .vs. a current source, as it will generally be providing less than the maximum safe current in order not to provide more than the maximum safe current under conditions (or for parts) where the forward voltage is particularly low.