Sesquiterpene synthase that catalyzes the formation of sesquiterpenes and sesquiterpenoid alcohols (PubMed:26744017). Converts farnesyl diphosphate (FPP) to hedycaryol (PubMed:26744017). Hedycaryol is likely to be one of the terpenes that attract insects for pollination of Camellia brevistyla (Probable). (2E,6E)-farnesyl diphosphate + H2O = (2E,6E)-hedycaryol + diphosphate Binds 3 Mg(2+) ions per subunit. Secondary metabolite biosynthesis; terpenoid biosynthesis. Specifically expressed in flowers. The Asp-Asp-Xaa-Xaa-Asp/Glu (DDXXD/E) motif is important for the catalytic activity, presumably through binding to Mg(2+). Belongs to the terpene synthase family.