Another place to get both real teas and flower or other teas, which I prefer to call tisanes, are these outlets. This one is very near my home, but I've never bought anything, despite its obvious popularity. It is called 瑶山凉茶 (yáo shān liáng chá) which literally means 'Jade Mountain Cold Tea'. This does not mean it is iced teas; just room temperature. Her selection includes some real tea, but most are tisanes.
Her shop is at the entrance to the local market, a busy place, so she does just fine, I guess. She stays open from early morning, well into the evening.
