The generic limits of some Verbenaceae and the familial circumscription have slightly changed in recent times. Glandularia, long included in Verbena, is nowadays accepted at the generic level (Sanders 2001, O’Leary & al. 2007, Mabberley 2008). Caryopteris and Clerodendrum, formerly thought to belong to Verbenaceae, are now accommodated in Lamiaceae (Cantino & al. 1992, Marx & al. 2010).
1. Stems creeping, rooting at the nodes. Fruit with 2 mericarps. Perennial === Phyla
1. Stems decumbent to erect, never creeping, rarely rooting at the lower nodes. Fruit with 4 mericarps. Annuals, biennials or perennials === 2
2. Leaves pinnatisect with linear-subulate lobes or merely serrate. Calyx twice as long as the mericarps with subulate-aristate teeth. Corolla salverform, showy, many flowering simultaneously. Stem decumbent, subterete === Glandularia
2. Leaves serrate-dentate or divided but never pinnatisect with linear lobes. Calyx not or only slightly exceeding the mericarps. Corolla funnelform, often rather inconspicuous, only few flowering at a time. Stem erect, quadrangular === Verbena
Cantino P.D., Harley A.M. & Wagstaff S.J. (1992) Genera of Labiatae: status and classification. In: Harley R.M. & Reynolds T. (eds.) Advances in labiate science. Royal Botanic Gardens, Kew: 511-522.
Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.
Marx H.E., O'Leary N., Yuan Y.-W., Lu-Irving P., Tank D.C., Mulgura M.E. & Olmstead R.G. (2010) A molecular phylogeny and classification of Verbenaceae. Am. J. Bot. 97(10): 1647-1663.
O’Leary N., Múlgura M.E. & Morrone O. (2007b) New Combinations in South American Glandularia (Verbenaceae). Novon 17(4): 503-511.
Sanders R.W. (2001) The genera of Verbenaceae in the Southeastern United States. Harvard Papers Bot. 5(2): 303-358.
Yuan Y.-W., Mabberley D.J., Steane D.A. & Olmstead R.G. (2010) Further disintegration and redefinition of Clerodendrum (Lamiaceae): implications for the understanding of the evolution of an intriguing breeding strategy. Taxon 59(1): 125-133.