If Yan Fei could bring out the yellow leaves of the tea tree, then he surely had tea trees.
They were located in the dinosaur world. Not many in number, but given the vastness of this world, even from the parts that he had explored, he could probably find around a thousand or so trees.
Not only did he find ancient tea trees over several thousand years old, he also located a small grove of tea trees. He initially wanted to transplant a few to his valley, but all the individual trees he found were ancient specimens — the young ones were simply too hard to find. When he finally found a young tea tree, it turned out to be part of a whole grove.
After some thought, Yan Fei figured he wouldn't use too much and didn't want to destroy this entire forest — who knew if it could grow as well as it was now after being transplanted? He decided to simply pick some, as long as it was enough for his own use.