Involved in the production of floral volatile phenylpropanoids in flowers of fragrant cultivars (e.g. cv. Mitchell and cv. V26) from cinnamic acid, a common precursor with the anthocyanin biosynthesis pathway involved in flower pigmentation (PubMed:26620524). Methylates caffeoyl-CoA to feruloyl-CoA, also able to methylate 5-hydroxyferuloyl-CoA (PubMed:26620524). (E)-caffeoyl-CoA + S-adenosyl-L-methionine = (E)-feruloyl-CoA + H(+) + S-adenosyl-L-homocysteine (E)-5-hydroxyferuloyl-CoA + S-adenosyl-L-methionine = (E)-sinapoyl-CoA + H(+) + S-adenosyl-L-homocysteine Binds 1 divalent metal cation per subunit. Aromatic compound metabolism; phenylpropanoid biosynthesis. Mostly expressed in petal limbs and tubes, and, at low levels, in flower buds, stamens, pistils, stems, roots and leaves. Accumulates during flower development with highest levels in open flowers, at anthesis, and fades out as flowers are senescing. Promoted by ODO1 (PubMed:26620524). Circadian-regulation with peak levels occurring in the afternoon in flowers (PubMed:26620524). Reduction of eugenol production but not of isoeugenol associated with abnormally purple-colored leaves and stems (e.g. especially in vascular bundles), and pink flowers due to the accumulation of anthocyanins (e.g. petunidin, delphinidin, malvidin and peonidin); purple floral buds and pink blush upon petals opening that fade in older flowers (PubMed:26620524). Disturbed CoA esters homeostasis and reduced lignin levels, but accumulation of anthocyanins associated with perturbated biosynthetic gene expression (PubMed:26620524). Belongs to the class I-like SAM-binding methyltransferase superfamily. Cation-dependent O-methyltransferase family. CCoAMT subfamily.