What in Europe is called 'black' tea in Asia is called 紅茶. In both cases its about a tea that has been rolled to induce an enzymatic oxidation that is left to complete. The brew is reddish, the leaves are black, and this is most likely the source of this confusion.
The character 滇 stands for the southwestern province of Yunnan. Traditionally, black teas are produced there that are consumed by the locals. This tea was developed in the 1920s, during the time of Japanese invasion, and originally made for export. It is sometimes also called 金針, because the fine hairs on the leaves turn gold during oxidation. The tea is marked by a floral aroma reminiscent of roses, hovering over the typical notes of cacao and malt.
This tea was purchased by the author at Shui Tang.