Problem in the generic delimitation between Alseodaphne, Dehaasia and Nothaphoebe (Lauraceae) in Borneo

Alseodaphne, Dehaasia and Nothaphoebe are, morphologically, three closely related genera belonging to the Persea subgroup of the Lauraceae. A total of 214 binomials of the three genera have been published by various authors (International Plant Names Index, March 2007), of which 44 have been attributed to species occurring in Borneo. In revising the Lauraceae for the Tree Flora of Sabah and Sarawak Project, we recognize 40 distinct species (i.e., Alseodaphne 11; Dehaasia 16; and Nothaphoebe 13) for Sabah and Sarawak. These include 34 previously known and 6 undescribed species. Despite many attempts by various authors (Rohwer 1993, 2000, Van der Werff & Richter 1996, Van der Werff 2001) to clarify the generic delimitation between these three genera, to date there remains to be no satisfactory solution. In the absence of a well-accepted generic delimitation and classification within the Lauraceae as a whole, and for the purpose of preparing revision of the Lauraceae for the Tree Flora of Sabah and Sarawak, we have opted for recognising Alseodaphne, Dehaasia and Nothaphoebe as distinct genera. The distinguishing morphological characters of these three genera, based on specimens from Borneo (Sabah and Sarawak, in particular) are presented.