Hanceola, Siphocranion and Isodon and Their Position in the Ocimeae (Labiatae)

In preparing an account of the Tribe Ocimeae Dumort. for Kubitzki's Families and Genera of Vascular Plants, it was noted that three closely related genera, Hanceola Kud6, Siphocranion Kud6 and Isodon (Benth.) Schrad. ex Spach, had an anomalous position within the tribe and did not fit neatly into the existing subtribes. This anomaly had already been highlighted by Ryding (1992, 1993a), who noted the difference in nutlet anatomy between these genera and the remainder of the tribe. This paper discusses the place of these genera within the tribe and concludes that they are best placed incertae sedis within the Ocimeae. A key to the subtribes of the Ocimeae and to genera incertae sedis is given.