Component of the monoterpenoid pyrethrins biosynthesis; pyrethrins are widely used plant-derived pesticide (PubMed:30468448). Catalyzes the condensation of two molecules of dimethylallyl diphosphate to produce chrysanthemyl diphosphate (CPP), a monoterpene with a non-head-to-tail or irregular c1'-2-3 linkage between isoprenoid units (PubMed:11287653, PubMed:25378387). In a second step, hydrolyzes the diphosphate moiety of CPP to form chrysanthemol (PubMed:25378387). With a lower efficiency, can also converts dimethylallyl diphosphate into lavandulyl diphosphate (LPP), and subsequently LPP into lavandulol (PubMed:25378387). 2 dimethylallyl diphosphate = (R,R)-chrysanthemyl diphosphate + diphosphate (R,R)-chrysanthemyl diphosphate + H2O = (R,R)-chrysanthemol + diphosphate (R)-lavandulyl diphosphate + H2O = (R)-lavandulol + diphosphate Binds 2 Mg(2+) ions per subunit. kcat is 0.5 min(-1) with dimethylallyl diphosphate as substrate (PubMed:11287653). kcat is 0.0033 min(-1) with chrysanthemyl diphosphate as substrate (PubMed:25378387). Optimum pH is 6.5-8. Isoprenoid biosynthesis. Restricted to glandular trichomes during achene maturation (PubMed:23104830). Expressed in flowers and in both ray and disk florets (PubMed:29122986). Mostly expressed in ovaries of flowers at stages S1 to S7 (bud to overblown), before the first disk florets opening, and prior embryos formation. Belongs to the FPP/GGPP synthase family.