Consider "Hallucinogenic Plants in Chinese Herbals" first published in Harvard University's Botanical Museum Leaflets in 1977:
So far as I know, there has been no report of any use of hallucinogenic plants in China in more modern times. We do not know whether the practice of using some plants by "sorcerers" or some other peoples as mentioned in earlier works occurred also in recent ages or not. It is not impossible that some use of hallucinogens may be found among the aborigines or other non-Han tribesmen along the remote borderlands in the southwest or elsewhere. There seems to be no such ethnobotanical study or survey ever having been made. We do come acress, however some records indicating that Cannabis was being used by the Uigurs [Uyghurs] along the Sinkiang (Chinese Turkestan) [Xinjiang] border in the remote northwest as late as the early twentieth century. (161–2)Li also argues, in his article "The Origin and Use of Cannabis in Eastern Asia Linguistic-Cultural Implications" (1974) that Chinese people do not consume marijuana because of the violence that is associated with the drug. Given that family is the guiding metaphor in Chinese culture (to address a group in Mandarin one states "dajia" [大家, big family]) this drug-induced violence would foreclose the plant's use. He suggests that perhaps "aborigines or other non-Han tribesmen along remote borderlands" might be consuming marijuana for its hallucinogenic affordances.
There are two things that are remarkable here: 1) that casual racism that Chinese-ness is Han-ness and 2) that to be properly "Chinese" (again, meaning "Han") one knows better than to use this plant in this prohibited manner.
The first item isn't so surprising perhaps—having worked as a researcher in Japan I was frequently confronted with this casual racism that pervades both Japan and China. In Japan, I've gone on record about the gaijin 外人 situation in Japan. In support of this casual racism in China I offer an anecdote from a very accomplished non-native Chinese researcher working in China for some time. Even after a long career in Chinese universities of top quality and after being presented with the most prestigious award one can receive as a non-native this researcher is still required to leave the country and renew their visa at great frequency. Permanent resident status has been denied over and again because of this lack of "Chinese-ness."
On the second point, it's not surprising that Li presents Chinese-ness as adhering to a common literature. Specifically, Li argues that it is the Zhongyong 中庸 (which he translates as Doctrine of the Mean) that proscribes deploying a technology that disrupts one's filial relations. Ignoring the colonial and racist origins of translating Zhongyong 中庸 as "doctrine of the mean," I am interested in what the Zhongyong states about the role of education in consummating one's position in relation to the cosmos. The Zhongyong is a technical manual about the cosmic powers attainable through a kind of learning. That to become enculturated (by observing certain ritualized technologies) is to become more human.
It's been about forty years since Li wrote his articles arguing for a cultural relating that defines "Chinese" as being Han and so we might imagine that since then there has been a sea change toward understanding China as a place as culturally diverse as Europe. But just this month an article was published in Science presenting a study discussing rice technologies vs. wheat technologies that explains the cultural differences between northern Han and southern Han. Again, Han-ness becomes a gloss for explaining cultural difference in "China."