WuYi tea is rather confusing to many tea drinkers. 2 main types of Wuyi tea by physical location of the trees: Rock teas and Zhou (Water side) teas. Rock teas are trees grown on cliffs of Wuyi mountain, Zhou teas are grown next to streams - lower altitude.
Here I talk about Rock teas briefly. Rock teas can be roughly divided into the following categories: Ming Cong (famous bush), varietals (produce large crops in tea farms), and Cai Cha (over all grouping of original local tea trees). Both Ming Cong and varietals are selections of good quality trees from Cai Cha. Before cloning was widely used to reproduce young trees, growing from seeds could not stabilize genetic, therefore Ming Congs are single bushes harvested, processed and sold uniquely. Other more stable varietals such as Shui Xian and Rou Gui can be widely sow and grown to produce large quantities.
Notorious names of Rock teas come to mind are: Da Hong Pao, Shui Jin Gui, Bai Ji Guan and so on. More than 800 varieties by name as currently known and documented by WuYi tea research institution. The name of the 800+ varieties can be separated according to myth (DHP), location (Zheng Huang Long), leaf shape (Bai Ji Guan), harvest time (Bu Zhi Chun), fragrance (Yue Gui), leaf color (Xiao Hong Mei), varietal (Shui Xian).
Da Hong Pao, despite its name which is widely known to many tea drinkers, the name is used for different concepts.
1) Ming Cong name - name for the group of 6 bushes. There are 6 single bushes (mother trees) still alive on the cliff of Tian Xin Cliff. These 6 bushes were sow from seeds, surviving centuries with its own individual genetic and flavor, even harvest time is different for each bush. Each bush is harvest individual and gone through a preliminary process, then combined all 6 together for final refined process (roasting), final product is about 1 kg each year. This is a blending technically speaking. 20g of DHP of these leave can be sold for $25k at auctions. The entire process is done by Wuyi tea research institute, we common tea drinkers will not have a chance laying our eyes on these precious leaves. They go straight to Zhong Nan Hai where the big shots are. Part of it is used for political purpose, such as the anual 20g DHP auction. Mao gifted half of his DHP to Nixon during his first visit to China in 1972, Nixon told his men that Mao was petty with such small quantity of tea. Little did he know, that's half of the "country" in Mao's words.
2) Varietal name - clones of the 6 DHP bushes now striving and producing in large quantity. In this case, DHP can be as pure as it can be or blended as well. Clones of one bush can be processed and sold on its own taking on the name DHP, or it can be blended with 2, 3, 4, 5 or all 6 of the clones to produce the end product also taking on the name DHP. In this case, varietal name and commercial product names are the same and legit.
3) Commercial product name - name of the end product on the market containing other than DHP varietal. Due to its famous mothers, demand for DHP increases substantially, to meet the market demand, some merchants blend DHP with other rock tea leaves and sold as DHP, or even without any DHP leaves.
Clones of "mother" trees are not exactly children where genetics can be evolved as sowing from seeds. Therefore, not considered as "generations". Clones contain the exact genetics, same flavor, same shape and same aroma. Ages of these clones are not to be mistaken as generations as well. i.e. clones done in the 80's are not "mothers" of the clones done in the 90's. However the age difference does make a significant contribution to Cha Qi. When shopping for DHP, some one tells you it's the second generation, therefore price is high is misleading.