What is done and what has to be done in Lamiaceae, a review of phylogenetics

The most recent classification proposed by Harley et al. in 2004 recognized seven subfamilies within the family Lamiaceae (Symphorematoideae, Viticoideae, Ajugoideae, Prostantheroideae, Scutellarioideae, Lamioideae and Nepetoideae). Symphorematoideae (formerly as part of Verbenaceae) is recognized as a subfamily of Lamiaceae for the first. Recognition of Viticoideae is one of the major modifications introduced in Harley’s treatment but yet it is the least satisfactory circumscribed subfamily which appeared to be clearly non-monophyletic. Subsequent studies based on molecular analysis also reported the non-monophyly of Viticoideae. New combinations are proposed in later studies at the generic level in subfamily Ajugoideae and Prostantheroideae. Suprageneric relationships among the Lamioideae remained poorly understood providing no tribal ranks in the Harley’s classification. Therefore, new tribes have been erected in the recent investigations to reflect improved phylogenetic undersanding of the Lamioideae. Subtribal delimitation of Mentheae (Nepetoideae) according to recent studies is not congruent with the Harley’s and new subtribes are recommended to establish the monophyly of Mentheae. Although the clade structure is relatively well established in the Lamiaceae, but tribal compositions remain unclear and needs to be further investigated to transform their taxonomy into a more ‘natural’ classification.