A new tribal classification of Nyctaginaceae

Recent phylogenetic work shows that existing tribal concepts within Nyctaginaceae are incompatible with the principle of recognizing monophyletic taxa. We review the history of supergeneric classification in Nyctaginaceae, clarify issues pertaining to priority of certain generic names, and discuss the application of the conserved family name to the tribe Nyctagineae. Pisoniella and Phaeoptilum are moved from tribe Nyctagineae to Pisonieae and Bougainvilleeae, respectively, while tribe Abronieae, containing Abronia and Tripterocalyx , is submerged into Nyctagineae. Two distinctive genera, Caribea and Colignonia , are assigned to their own tribes, recognizing both their uniqueness and the uncertainty of their phylogenetic relationships. Finally, subtribes are not recognized in tribe Nyctagineae. Updated descriptions are provided for each tribe and one new tribe, Caribeaeae Douglas & Spellenberg, is recognized. Plant habit and general geographic distribution seem to be at least as pertinent as the often–homoplasious morphological details which had been emphasized in previous classifications.