Was trying to check the net to find which "legal highs" are legal in HK and which are not. Salvia Divinorum was added into prohibited items under dangerous drugs in 2012. While I cannot find Psilocin listed in the prohibited plants or drugs, Customs website does have an article from 2005 boasting about "HK first bust of magic mushrooms".
How about Morning Glory? Cannot find any mention on Customs website. Apparently seeds can still be bought in any gardening shop, but those are often coated with dangerous chemicals to discourage 'creative' use.
So where is HK with this currently? Strict control over suspicious small brown packages from Canada or Netherlands, while more traditional drugs like cocaine and hash are abundant in TST around Chungking Mansions, to the ire of all passing white guys whether interested or not?