Oolong Tea Names in Taiwan: Varietals, Regions, and Styles
All tea is all made from the same species of plant, Camellia Sinensis. There are different varietals. The difference between green, oolong, and black tea is the processing method used after harvest. For more on that see "oxidation".
As far as oolong flavor, all things being equal—elevation, oxidation, cultivar, and roasting are all factors. Of course seasons, weather, farming and processing methods all play a part as well.
Here's a summary on Taiwanese Oolongs. In Taiwan varietal, region, and processing style all play a part in the name of the tea. Sometimes you will see names translated into English, for example: Dong Ding = Frozen Summit or Lugu = Deer Valley.
There are a number of varietals developed in Taiwan by the government subsidized TRES (Tea Research Extension Station). The ‘original’ strain is called ‘Qing Xin Oolong’. If a tea is simply called ‘oolong’, chances are it is Qing Xin Oolong. Jin Xuan and Tsui Yu are two very popular and well know newer varietals. Jin Xuan is known for being smooth, milky, and buttery. Tsui Yu is known for being fresh and floral.
Alishan, Lugu, and LiShan are three very well known Taiwanese tea growing regions, each having it’s own unique reputation. Each region may have its own weather system, terroir, traditional tea making style, and elevation. There are many more tea growing regions in Taiwan, a discussion of which would warrant an entire thread.
An example of a popular style is ‘Dong Ding Oolong’. Originally named so because it was developed on Dong Ding Mountain (in Lugu), Dong Ding Oolong is a well oxidized and roasted oolong tea. This is an example of a place name that has evolved into a style name. Most commonly you’ll find Dong Ding made with Qing Xin oolong, but Jin Xuan Dong Ding is also quite popular.