It really bothers me seeing that flower tea being called "jasmine tea". That flower is not jasmine. There are flowering teas that contain jasmine in the bundle, but either way plain old "jasmine tea" does not look like that.
Since this error was present in both manga adaptations, I can only assume the flaw originated in the textual description of the novel, and the manga artists only followed the original text. I think what the author calls "jasmine tea 茉莉花茶" is actually "茉莉仙桃" (literally translates to "jasmine peach"). 茉莉仙桃 is a specific flowering jasmine tea that's made with amaranth flower as the centrepiece. I don't think 茉莉仙桃 should be referred to with "jasmine tea", but I don't know. Maybe there are Japanese sites that mislabelled the product or in Japan people just call it differently.
This is a 茉莉仙桃, which resembles the flower depicted in the artwork more closely:
This is a blooming tea with both chrysanthemum and jasmine blossoms:
The big yellow flower is chrysanthemum. The jasmine is the smaller white flower on top.
Regular jasmine tea with jasmine blossoms that are not made into a blooming tea bundle: